[GH-ISSUE #468] 405 error against local Baikal CalDAV server #1316

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opened 2026-03-14 00:57:50 +03:00 by kerem · 0 comments

kerem commented

2026-03-14 00:57:50 +03:00

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Originally created by @mspgrunt on GitHub (Mar 13, 2026).
Original GitHub issue: https://github.com/aluxnimm/outlookcaldavsynchronizer/issues/468

Error message in Outlook:

Sanity check, I can connect to my calendar fine within One Calendar app:

Big long error message that I get when trying to sync anyways:

CalDavSynchronizer.DataAccess.WebDavClientException: Response status code does not indicate success: '405' ('Method Not Allowed'). Message:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html><head>
<title>405 Method Not Allowed</title>
</head><body>
<h1>Method Not Allowed</h1>
<p>The requested method REPORT is not allowed for this URL.</p>
<hr>
<address>Apache/2.4.66 (Debian) Server at 192.168.8.157 Port 80</address>
</body></html>

   at CalDavSynchronizer.DataAccess.HttpClientBasedClient.WebDavClient.<EnsureSuccessStatusCode>d__10.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at CalDavSynchronizer.DataAccess.HttpClientBasedClient.WebDavClient.<ExecuteWebDavRequest>d__9.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at CalDavSynchronizer.DataAccess.HttpClientBasedClient.WebDavClient.<ExecuteWebDavRequestAndReadResponse>d__7.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at CalDavSynchronizer.DataAccess.CalDavDataAccess.<GetVersions>d__29.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at CalDavSynchronizer.DataAccess.CalDavDataAccess.<GetVersions>d__29.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at CalDavSynchronizer.Implementation.CalDavRepository`1.<GetAllVersions>d__9.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at GenSync.EntityRepositories.VersionAwareToStateAwareEntityRepositoryAdapter`4.<GetFullRepositoryState>d__5.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at GenSync.Synchronization.Synchronizer`11.<Synchronize>d__27.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at GenSync.Synchronization.ContextCreatingSynchronizerDecorator`7.<Synchronize>d__3.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at CalDavSynchronizer.Scheduling.SynchronizationProfileRunner.<RunAndRescheduleNoThrow>d__22.MoveNext()

I found this which seemed similar at a glance, https://github.com/aluxnimm/outlookcaldavsynchronizer/issues/249, but after reducing time range to ridiculous small range (2 days before, 2 days after) there was no change in behavior

Originally created by @mspgrunt on GitHub (Mar 13, 2026). Original GitHub issue: https://github.com/aluxnimm/outlookcaldavsynchronizer/issues/468 Error message in Outlook: <img width="839" height="703" alt="Image" src="https://github.com/user-attachments/assets/ab379f99-f89c-49bc-bcd2-104125976b13" /> Sanity check, I can connect to my calendar fine within One Calendar app: <img width="1184" height="925" alt="Image" src="https://github.com/user-attachments/assets/aeef3a97-d48c-41cb-b624-97f0ce84ffaa" /> Big long error message that I get when trying to sync anyways: ``` CalDavSynchronizer.DataAccess.WebDavClientException: Response status code does not indicate success: '405' ('Method Not Allowed'). Message: <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd"> <html><head> <title>405 Method Not Allowed</title> </head><body> <h1>Method Not Allowed</h1> <p>The requested method REPORT is not allowed for this URL.</p> <hr> <address>Apache/2.4.66 (Debian) Server at 192.168.8.157 Port 80</address> </body></html> at CalDavSynchronizer.DataAccess.HttpClientBasedClient.WebDavClient.<EnsureSuccessStatusCode>d__10.MoveNext() --- End of stack trace from previous location where exception was thrown --- at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) at CalDavSynchronizer.DataAccess.HttpClientBasedClient.WebDavClient.<ExecuteWebDavRequest>d__9.MoveNext() --- End of stack trace from previous location where exception was thrown --- at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) at CalDavSynchronizer.DataAccess.HttpClientBasedClient.WebDavClient.<ExecuteWebDavRequestAndReadResponse>d__7.MoveNext() --- End of stack trace from previous location where exception was thrown --- at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) at CalDavSynchronizer.DataAccess.CalDavDataAccess.<GetVersions>d__29.MoveNext() --- End of stack trace from previous location where exception was thrown --- at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() at CalDavSynchronizer.DataAccess.CalDavDataAccess.<GetVersions>d__29.MoveNext() --- End of stack trace from previous location where exception was thrown --- at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) at CalDavSynchronizer.Implementation.CalDavRepository`1.<GetAllVersions>d__9.MoveNext() --- End of stack trace from previous location where exception was thrown --- at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) at GenSync.EntityRepositories.VersionAwareToStateAwareEntityRepositoryAdapter`4.<GetFullRepositoryState>d__5.MoveNext() --- End of stack trace from previous location where exception was thrown --- at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) at GenSync.Synchronization.Synchronizer`11.<Synchronize>d__27.MoveNext() --- End of stack trace from previous location where exception was thrown --- at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) at GenSync.Synchronization.ContextCreatingSynchronizerDecorator`7.<Synchronize>d__3.MoveNext() --- End of stack trace from previous location where exception was thrown --- at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) at CalDavSynchronizer.Scheduling.SynchronizationProfileRunner.<RunAndRescheduleNoThrow>d__22.MoveNext() ``` I found this which seemed similar at a glance, https://github.com/aluxnimm/outlookcaldavsynchronizer/issues/249, but after reducing time range to ridiculous small range (2 days before, 2 days after) there was no change in behavior