[GH-ISSUE #107] Null reference exception at DDay.iCal.iCalTimeZoneInfo #104

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opened 2026-02-25 20:30:54 +03:00 by kerem · 4 comments

kerem commented

2026-02-25 20:30:54 +03:00

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Originally created by @schtritoff on GitHub (Jan 26, 2016).
Original GitHub issue: https://github.com/aluxnimm/outlookcaldavsynchronizer/issues/107

I'm getting exception in Synchronization Reports for every sync (version 1.14.2, caldav server sabre/dav 3.0.7), below are details. This problem showed up recently (version 1.13 was ok I think).

<?xml version="1.0" encoding="utf-16"?>
<SynchronizationReport xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <ProfileName>some profile</ProfileName>
  <ProfileId>2f7cecaf-e114-46b6-a678-481fa2115211</ProfileId>
  <StartTime>2016-01-26T12:49:49.6454561Z</StartTime>
  <InitialEntityMatchingPerformed>false</InitialEntityMatchingPerformed>
  <LoadErrors />
  <EntitySynchronizationReports />
  <ExceptionThatLeadToAbortion>System.NullReferenceException: Object reference not set to an instance of an object.
   at DDay.iCal.iCalTimeZoneInfo.&lt;&gt;c__DisplayClass2.&lt;GetObservance&gt;b__0(IPeriod p)
   at System.Linq.Enumerable.FirstOrDefault[TSource](IEnumerable`1 source, Func`2 predicate)
   at DDay.iCal.iCalTimeZoneInfo.GetObservance(IDateTime dt)
   at DDay.iCal.iCalTimeZone.GetTimeZoneObservance(IDateTime dt)
   at DDay.iCal.iCalDateTime.GetTimeZoneObservance()
   at DDay.iCal.iCalDateTime.get_UTC()
   at CalDavSynchronizer.Implementation.Events.InitialEventEntityMatcher.AreEqual(AppointmentItemWrapper atypeEntity, IICalendar btypeEntity)
   at GenSync.InitialEntityMatching.InitialEntityMatcherByPropertyGrouping`8.FindMatchingEntities(IEntityRelationDataFactory`4 relationFactory, IReadOnlyDictionary`2 allAtypeEntities, IReadOnlyDictionary`2 allBtypeEntities, IReadOnlyDictionary`2 atypeEntityVersions, IReadOnlyDictionary`2 btypeEntityVersions)
   at GenSync.Synchronization.Synchronizer`6.&lt;Synchronize&gt;d__3a.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd(Task task)
   at GenSync.Synchronization.Synchronizer`6.&lt;SynchronizeNoThrow&gt;d__4.MoveNext()</ExceptionThatLeadToAbortion>
  <Duration>00:00:02.3060000</Duration>
</SynchronizationReport>

Originally created by @schtritoff on GitHub (Jan 26, 2016). Original GitHub issue: https://github.com/aluxnimm/outlookcaldavsynchronizer/issues/107 I'm getting exception in Synchronization Reports for every sync (version 1.14.2, caldav server sabre/dav 3.0.7), below are details. This problem showed up recently (version 1.13 was ok I think). ``` <?xml version="1.0" encoding="utf-16"?> <SynchronizationReport xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"> <ProfileName>some profile</ProfileName> <ProfileId>2f7cecaf-e114-46b6-a678-481fa2115211</ProfileId> <StartTime>2016-01-26T12:49:49.6454561Z</StartTime> <InitialEntityMatchingPerformed>false</InitialEntityMatchingPerformed> <LoadErrors /> <EntitySynchronizationReports /> <ExceptionThatLeadToAbortion>System.NullReferenceException: Object reference not set to an instance of an object. at DDay.iCal.iCalTimeZoneInfo.<>c__DisplayClass2.<GetObservance>b__0(IPeriod p) at System.Linq.Enumerable.FirstOrDefault[TSource](IEnumerable`1 source, Func`2 predicate) at DDay.iCal.iCalTimeZoneInfo.GetObservance(IDateTime dt) at DDay.iCal.iCalTimeZone.GetTimeZoneObservance(IDateTime dt) at DDay.iCal.iCalDateTime.GetTimeZoneObservance() at DDay.iCal.iCalDateTime.get_UTC() at CalDavSynchronizer.Implementation.Events.InitialEventEntityMatcher.AreEqual(AppointmentItemWrapper atypeEntity, IICalendar btypeEntity) at GenSync.InitialEntityMatching.InitialEntityMatcherByPropertyGrouping`8.FindMatchingEntities(IEntityRelationDataFactory`4 relationFactory, IReadOnlyDictionary`2 allAtypeEntities, IReadOnlyDictionary`2 allBtypeEntities, IReadOnlyDictionary`2 atypeEntityVersions, IReadOnlyDictionary`2 btypeEntityVersions) at GenSync.Synchronization.Synchronizer`6.<Synchronize>d__3a.MoveNext() --- End of stack trace from previous location where exception was thrown --- at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd(Task task) at GenSync.Synchronization.Synchronizer`6.<SynchronizeNoThrow>d__4.MoveNext()</ExceptionThatLeadToAbortion> <Duration>00:00:02.3060000</Duration> </SynchronizationReport> ```

kerem closed this issue

2026-02-25 20:30:54 +03:00

kerem commented

2026-02-25 20:30:54 +03:00

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@aluxnimm commented on GitHub (Jan 26, 2016):

Can you provide the ics file of a calendar event from your server which causes this issue? What timezone are you using? Does this also happen when you sync your server calendar oneway into an empty outlook folder?

@aluxnimm commented on GitHub (Jan 26, 2016): Can you provide the ics file of a calendar event from your server which causes this issue? What timezone are you using? Does this also happen when you sync your server calendar oneway into an empty outlook folder?

kerem commented

2026-02-25 20:30:54 +03:00

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@schtritoff commented on GitHub (Jan 26, 2016):

I've just created new outlook calendar in the same outlook profile then copied caldav sync profile to test with new calendan and there are no errors.
Can't tell which ics file is causing problems. My timezone (Windows PC) is UTC+01:00.

@schtritoff commented on GitHub (Jan 26, 2016): I've just created new outlook calendar in the same outlook profile then copied caldav sync profile to test with new calendan and there are no errors. Can't tell which ics file is causing problems. My timezone (Windows PC) is UTC+01:00.

kerem commented

2026-02-25 20:30:54 +03:00

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@aluxnimm commented on GitHub (Jan 28, 2016):

can't reproduce without the server data, but atleast a workaround is possible.

@aluxnimm commented on GitHub (Jan 28, 2016): can't reproduce without the server data, but atleast a workaround is possible.

kerem commented

2026-02-25 20:30:54 +03:00

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@schtritoff commented on GitHub (Feb 8, 2016):

Since version 1.15, it looks like it's fixed now.

@schtritoff commented on GitHub (Feb 8, 2016): Since version 1.15, it looks like it's fixed now.

kerem referenced this issue

2026-02-25 20:31:05 +03:00

[GH-ISSUE #181] Make the "unable to connect to remote server" message less intrusive #178

kerem referenced this issue

2026-03-01 17:39:57 +03:00