[GH-ISSUE #1814] Syncing failed with Cannot read properties of undefined (reading 'filter')

kerem commented

2026-02-25 22:39:20 +03:00

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Originally created by @alfredonodo on GitHub (Jan 5, 2025).
Original GitHub issue: https://github.com/floccusaddon/floccus/issues/1814

Which version of floccus are you using?

5.4.0

How many bookmarks do you have, roughly?

1000

Are you using other means to sync bookmarks in parallel to floccus?

No

Sync method

WebDAV

Which browser are you using? In case you are using the phone App, specify the Android or iOS version and device please.

LibreWolf 133.0.3-1, Brave nightly 1.75.142

Which version of Nextcloud Bookmarks are you using? (if relevant)

No response

Which version of Nextcloud? (if relevant)

No response

What kind of WebDAV server are you using? (if relevant)

wölkli nextcloud free

Describe the Bug

LibreWolf is able to synchronise to the cloud while Brave as of today no longer synchronises and I get.

2025-01-05T10:13:45.270Z Starting sync process for account 
2025-01-05T10:13:45.275Z onSyncStart: begin
2025-01-05T10:13:46.916Z onSyncStart: completed
2025-01-05T10:13:46.997Z Failed to load pending continuation. Continuing with normal sync
2025-01-05T10:13:46.997Z Using "merge slave" strategy (no cache available)
2025-01-05T10:13:46.997Z Retrieving local tree
2025-01-05T10:13:47.000Z Filtering out unaccepted local bookmarks
2025-01-05T10:13:47.000Z Syncing failed with Cannot read properties of undefined (reading 'filter')
2025-01-05T10:13:47.002Z onSyncFail

Expected Behavior

A correct synchronisation that worked well until 1 month ago.

To Reproduce

Install LibreWolf, Brave and Floccus
Synchronise LibreWolf to the cloud
Synchronise the cloud to Brave

Debug log provided

I have provided a debug log file

Originally created by @alfredonodo on GitHub (Jan 5, 2025). Original GitHub issue: https://github.com/floccusaddon/floccus/issues/1814 ### Which version of floccus are you using? 5.4.0 ### How many bookmarks do you have, roughly? 1000 ### Are you using other means to sync bookmarks in parallel to floccus? No ### Sync method WebDAV ### Which browser are you using? In case you are using the phone App, specify the Android or iOS version and device please. LibreWolf 133.0.3-1, Brave nightly 1.75.142 ### Which version of Nextcloud Bookmarks are you using? (if relevant) _No response_ ### Which version of Nextcloud? (if relevant) _No response_ ### What kind of WebDAV server are you using? (if relevant) wölkli nextcloud free ### Describe the Bug LibreWolf is able to synchronise to the cloud while Brave as of today no longer synchronises and I get. ``` 2025-01-05T10:13:45.270Z Starting sync process for account 2025-01-05T10:13:45.275Z onSyncStart: begin 2025-01-05T10:13:46.916Z onSyncStart: completed 2025-01-05T10:13:46.997Z Failed to load pending continuation. Continuing with normal sync 2025-01-05T10:13:46.997Z Using "merge slave" strategy (no cache available) 2025-01-05T10:13:46.997Z Retrieving local tree 2025-01-05T10:13:47.000Z Filtering out unaccepted local bookmarks 2025-01-05T10:13:47.000Z Syncing failed with Cannot read properties of undefined (reading 'filter') 2025-01-05T10:13:47.002Z onSyncFail ``` ### Expected Behavior A correct synchronisation that worked well until 1 month ago. ### To Reproduce 1. Install LibreWolf, Brave and Floccus 2. Synchronise LibreWolf to the cloud 3. Synchronise the cloud to Brave ### Debug log provided - [X] I have provided a debug log file

kerem

2026-02-25 22:39:20 +03:00

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kerem commented

2026-02-25 22:39:21 +03:00

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@github-actions[bot] commented on GitHub (Jan 5, 2025):

Hello 👋

Thank you for taking the time to open this issue with floccus. I know it's frustrating when software
causes problems. You have made the right choice to come here and open an issue to make sure your problem gets looked at
and if possible solved.
I'm Marcel and I created floccus a few years ago, maintaining it ever since. I currently work for Nextcloud
which leaves me with less time for side projects like this one than I used to have.
I still try to answer all issues and if possible fix all bugs here, but it sometimes takes a while until I get to it.
Until then, please be patient.
Note also that GitHub is a place where people meet to make software better together. Nobody here is under any obligation
to help you, solve your problems or deliver on any expectations or demands you may have, but if enough people come together we can
collaborate to make this software better. For everyone.
Thus, if you can, you could also have a look at other issues to see whether you can help other people with your knowledge
and experience. If you have coding experience it would also be awesome if you could step up to dive into the code and
try to fix the odd bug yourself. Everyone will be thankful for extra helping hands!
To continue the development and maintenance of this project in a sustainable way it is expected that you donate to the project when opening a ticket,
if you're not a donor already. You can find donation options at https://floccus.org/donate/. Thank you!

One last word: If you feel, at any point, like you need to vent, this is not the place for it; you can go to the Nextcloud forum,
to twitter or somewhere else. But this is a technical issue tracker, so please make sure to
focus on the tech and keep your opinions to yourself.

I look forward to working with you on this issue
Cheers 💙

@github-actions[bot] commented on GitHub (Jan 5, 2025): Hello :wave: Thank you for taking the time to open this issue with floccus. I know it's frustrating when software causes problems. You have made the right choice to come here and open an issue to make sure your problem gets looked at and if possible solved. I'm Marcel and I created floccus a few years ago, maintaining it ever since. I currently work for Nextcloud which leaves me with less time for side projects like this one than I used to have. I still try to answer all issues and if possible fix all bugs here, but it sometimes takes a while until I get to it. Until then, please be patient. Note also that GitHub is a place where people meet to make software better *together*. Nobody here is under any obligation to help you, solve your problems or deliver on any expectations or demands you may have, but if enough people come together we can collaborate to make this software better. For everyone. Thus, if you can, you could also have a look at other issues to see whether you can help other people with your knowledge and experience. If you have coding experience it would also be awesome if you could step up to dive into the code and try to fix the odd bug yourself. Everyone will be thankful for extra helping hands! To continue the development and maintenance of this project in a sustainable way it is expected that you donate to the project when opening a ticket, if you're not a donor already. You can find donation options at <https://floccus.org/donate/>. Thank you! One last word: If you feel, at any point, like you need to vent, this is not the place for it; you can go to the Nextcloud forum, to twitter or somewhere else. But this is a technical issue tracker, so please make sure to focus on the tech and keep your opinions to yourself. I look forward to working with you on this issue Cheers :blue_heart:

kerem commented

2026-02-25 22:39:21 +03:00

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@marcelklehr commented on GitHub (Jan 6, 2025):

mmmh, I cannot reproduce this with Brave 1.73.104 (Chromium: 131.0.6778.204 (Official Build)), can you try with Brave non-nightly?

@marcelklehr commented on GitHub (Jan 6, 2025): mmmh, I cannot reproduce this with Brave 1.73.104 (Chromium: 131.0.6778.204 (Official Build)), can you try with Brave non-nightly?

kerem commented

2026-02-25 22:39:21 +03:00

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@ThubLives commented on GitHub (Jan 8, 2025):

My debug log looks pretty much identical, though I'm using Chrome. Apparently it's been failing for 5 months now.

Floccus 5.4.0
Chrome 131.0.6778.206 (Official Build) (64-bit)

@ThubLives commented on GitHub (Jan 8, 2025): My debug log looks pretty much identical, though I'm using Chrome. Apparently it's been failing for 5 months now. Floccus 5.4.0 Chrome 131.0.6778.206 (Official Build) (64-bit)

kerem commented

2026-02-25 22:39:21 +03:00

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@marcelklehr commented on GitHub (Jan 12, 2025):

Ok, so it's not a Brave issue, then.

@marcelklehr commented on GitHub (Jan 12, 2025): Ok, so it's not a Brave issue, then.

kerem commented

2026-02-25 22:39:21 +03:00

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@marcelklehr commented on GitHub (Jan 12, 2025):

@GrantRobertson has the same on Chrome https://github.com/floccusaddon/floccus/issues/1823

@marcelklehr commented on GitHub (Jan 12, 2025): @GrantRobertson has the same on Chrome https://github.com/floccusaddon/floccus/issues/1823

kerem commented

2026-02-25 22:39:21 +03:00

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@marcelklehr commented on GitHub (Jan 12, 2025):

Do you all happen to have multiple possibly nested profiles in floccus? Possibly with nested sync disabled in some of them?

@marcelklehr commented on GitHub (Jan 12, 2025): Do you all happen to have multiple possibly nested profiles in floccus? Possibly with nested sync disabled in some of them?

kerem commented

2026-02-25 22:39:21 +03:00

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@GrantRobertson commented on GitHub (Jan 12, 2025):

Do you all happen to have multiple possibly nested profiles in floccus? Possibly with nested sync disabled in some of them?

I just had the most basic of installs. No special anything. I literally just installed the extension, kept the defaults, and tried to sync all of my bookmarks up to your service.

@GrantRobertson commented on GitHub (Jan 12, 2025): > Do you all happen to have multiple possibly nested profiles in floccus? Possibly with nested sync disabled in some of them? I just had the most basic of installs. No special anything. I literally just installed the extension, kept the defaults, and tried to sync all of my bookmarks up to your service.

kerem commented

2026-02-25 22:39:21 +03:00

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@marcelklehr commented on GitHub (Jan 12, 2025):

@GrantRobertson did you export the profile from a different browser and import it to another one where it then didn't work? Which Bookmarks folder did you select to be synced?

@marcelklehr commented on GitHub (Jan 12, 2025): @GrantRobertson did you export the profile from a different browser and import it to another one where it then didn't work? Which Bookmarks folder did you select to be synced?

kerem commented

2026-02-25 22:39:21 +03:00

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@GrantRobertson commented on GitHub (Jan 12, 2025):

@GrantRobertson did you export the profile from a different browser and import it to another one where it then didn't work? Which Bookmarks folder did you select to be synced?

@marcelklehr Nope. This was literally my first try at using the software. I just selected the root folder of my bookmarks, as suggested in the documentation.

@GrantRobertson commented on GitHub (Jan 12, 2025): > @GrantRobertson did you export the profile from a different browser and import it to another one where it then didn't work? Which Bookmarks folder did you select to be synced? @marcelklehr Nope. This was literally my first try at using the software. I just selected the root folder of my bookmarks, as suggested in the documentation.

kerem commented

2026-02-25 22:39:21 +03:00

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@marcelklehr commented on GitHub (Jan 12, 2025):

Huh. I'm stumped. I cannot reproduce this. headscratch

There seems to be some inconsistency in your bookmarks somehow.

@marcelklehr commented on GitHub (Jan 12, 2025): Huh. I'm stumped. I cannot reproduce this. *headscratch* There seems to be some inconsistency in your bookmarks somehow.

kerem commented

2026-02-25 22:39:21 +03:00

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@GrantRobertson commented on GitHub (Jan 12, 2025):

Huh. I'm stumped.

@marcelklehr When I chose the root directory, your dialog box showed the name of that folder as "Undefined" or something like that. I am pretty sure that I also tried simply synchronizing the "Bookmarks Bar" folder, but I got the same error, so I switched back to having selected the root.

I do have a gigantic buttload of old bookmarks, going all the way back to when I was using Netscape Navigator, back in the olden times. I just keep importing old bookmarks when I switch to a new browser. However, I have been using Chrome exclusively for over a decade, IIRC. And, one would expect that the import process would have cleaned up any funky bookmark entries from previous browsers.

@GrantRobertson commented on GitHub (Jan 12, 2025): > Huh. I'm stumped. @marcelklehr When I chose the root directory, your dialog box showed the name of that folder as "Undefined" or something like that. I am pretty sure that I also tried simply synchronizing the "Bookmarks Bar" folder, but I got the same error, so I switched back to having selected the root. I do have a gigantic buttload of old bookmarks, going all the way back to when I was using Netscape Navigator, back in the olden times. I just keep importing old bookmarks when I switch to a new browser. However, I have been using Chrome exclusively for over a decade, IIRC. And, one would expect that the import process would have cleaned up any funky bookmark entries from previous browsers.

kerem commented

2026-02-25 22:39:21 +03:00

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@marcelklehr commented on GitHub (Jan 12, 2025):

@GrantRobertson Can you perhaps try creating a new profile and see if it works there? (Not sure how/if that works on chrome)

@marcelklehr commented on GitHub (Jan 12, 2025): @GrantRobertson Can you perhaps try creating a new profile and see if it works there? (Not sure how/if that works on chrome)

kerem commented

2026-02-25 22:39:21 +03:00

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@GrantRobertson commented on GitHub (Jan 12, 2025):

@GrantRobertson Can you perhaps try creating a new profile and see if it works there? (Not sure how/if that works on chrome)

I've got other Chrome profiles that I could try it on. But I'm not super inclined, at this point. I need to get breakfast. I may try it later.

If it did work on some other profile, Floccus would still be of little benefit to me, because that would still mean that I would have to clean up and purge my main bookmarks collection before I could synchronize it to my other Chrome profiles. And I am totally not up for that chore today. I have kind of just accepted that I will have to just keep the bookmarks separate for each profile. I created my other Chrome profiles, mostly, just to be able to easily log into a small set of different websites where I have multiple accounts (like Reddit), without needing to constantly log out then back in under different accounts. So, I really only need to have just a few bookmarks for those other Chrome profiles.

Trying Floccus was mostly just the result of me diving a bit too deep down a rabbit hole that I kinda didn't need to go down anyway. You know how that goes.

@GrantRobertson commented on GitHub (Jan 12, 2025): > @GrantRobertson Can you perhaps try creating a new profile and see if it works there? (Not sure how/if that works on chrome) I've got other Chrome profiles that I could try it on. But I'm not super inclined, at this point. I need to get breakfast. I may try it later. If it did work on some other profile, Floccus would still be of little benefit to me, because that would still mean that I would have to clean up and purge my main bookmarks collection before I could synchronize it to my other Chrome profiles. And I am totally not up for that chore today. I have kind of just accepted that I will have to just keep the bookmarks separate for each profile. I created my other Chrome profiles, mostly, just to be able to easily log into a small set of different websites where I have multiple accounts (like Reddit), without needing to constantly log out then back in under different accounts. So, I really only **need** to have just a few bookmarks for those other Chrome profiles. Trying Floccus was mostly just the result of me diving a bit too deep down a rabbit hole that I kinda didn't need to go down anyway. You know how that goes.

kerem commented

2026-02-25 22:39:21 +03:00

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@marcelklehr commented on GitHub (Feb 4, 2025):

~~I was able to reproduce this now.~~ Scratch that, it was just a fluke.

@marcelklehr commented on GitHub (Feb 4, 2025): ~~I was able to reproduce this now.~~ Scratch that, it was just a fluke.

kerem commented

2026-02-25 22:39:21 +03:00

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@marcelklehr commented on GitHub (Feb 5, 2025):

Do you all have any other bookmarks related extensions/addons enabled, perhaps?

@marcelklehr commented on GitHub (Feb 5, 2025): Do you all have any other bookmarks related extensions/addons enabled, perhaps?

kerem commented

2026-02-25 22:39:21 +03:00

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@wakmail commented on GitHub (Feb 27, 2025):

Hey, I just discovered the same issue, it says E002: Bookmark to update doesn't exist anymore | Last synchronized: 2 weeks ago

@wakmail commented on GitHub (Feb 27, 2025): Hey, I just discovered the same issue, it says ```E002: Bookmark to update doesn't exist anymore | Last synchronized: 2 weeks ago```

kerem commented

2026-02-25 22:39:21 +03:00

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@wakmail commented on GitHub (Feb 27, 2025):

I just reinstalled the extension and that fixed it.

@wakmail commented on GitHub (Feb 27, 2025): I just reinstalled the extension and that fixed it.

kerem commented

2026-02-25 22:39:21 +03:00

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@github-actions[bot] commented on GitHub (May 29, 2025):

Hello 👋
This issue appears to have had no activity for 3 months. We cannot keep track of whether individual issues
have resolved themselves or still require attention without user interaction. We're thus adding the stale label to this issue to schedule
it for getting closed in 5 days time. If you believe this issue is still valid and should be fixed, you can add a comment
or remove the label to avoid it getting closed.

Cheers 💙

@github-actions[bot] commented on GitHub (May 29, 2025): Hello :wave: This issue appears to have had no activity for 3 months. We cannot keep track of whether individual issues have resolved themselves or still require attention without user interaction. We're thus adding the stale label to this issue to schedule it for getting closed in 5 days time. If you believe this issue is still valid and should be fixed, you can add a comment or remove the label to avoid it getting closed. Cheers :blue_heart:

kerem commented

2026-02-25 22:39:21 +03:00

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@github-actions[bot] commented on GitHub (Jun 3, 2025):

This issue was closed because it has been stalled for 5 days with no activity.

@github-actions[bot] commented on GitHub (Jun 3, 2025): This issue was closed because it has been stalled for 5 days with no activity.

kerem commented

2026-02-25 22:39:21 +03:00

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@Eyion commented on GitHub (Aug 27, 2025):

By the way, when I was using Android 5.6.0, I couldn't sync bookmarks from the WebDAV server. When I updated to Android 5.7.0, I was able to sync, but the page display (including the About, Options, and Tags sub-directories) didn't fit the screen, appearing only to the left and taking up half the screen. Additionally, no matter which sub-directory, the pull-down action didn't respond.

@Eyion commented on GitHub (Aug 27, 2025): By the way, when I was using Android 5.6.0, I couldn't sync bookmarks from the WebDAV server. When I updated to Android 5.7.0, I was able to sync, but the page display (including the About, Options, and Tags sub-directories) didn't fit the screen, appearing only to the left and taking up half the screen. Additionally, no matter which sub-directory, the pull-down action didn't respond.

kerem commented

2026-02-25 22:39:21 +03:00

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@marcelklehr commented on GitHub (Aug 27, 2025):

Hey @Eyion
Thank you for taking the time to give feedback! Can you open a new issue for these visual problems, ideally with screenshots?

@marcelklehr commented on GitHub (Aug 27, 2025): Hey @Eyion Thank you for taking the time to give feedback! Can you open a new issue for these visual problems, ideally with screenshots?

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[GH-ISSUE #1814] Syncing failed with Cannot read properties of undefined (reading 'filter') #1215

Which version of floccus are you using?

How many bookmarks do you have, roughly?

Are you using other means to sync bookmarks in parallel to floccus?

Sync method

Which browser are you using? In case you are using the phone App, specify the Android or iOS version and device please.

Which version of Nextcloud Bookmarks are you using? (if relevant)

Which version of Nextcloud? (if relevant)

What kind of WebDAV server are you using? (if relevant)

Describe the Bug

Expected Behavior

To Reproduce

Debug log provided