[GH-ISSUE #360] System.Net.WebException: The server committed a protocol violation. Section=ResponseHeader Detail=CR must be followed by LF #815

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opened 2026-03-01 17:41:43 +03:00 by kerem · 1 comment

kerem commented

2026-03-01 17:41:43 +03:00

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Originally created by @Hafnernuss on GitHub (Jun 14, 2022).
Original GitHub issue: https://github.com/aluxnimm/outlookcaldavsynchronizer/issues/360

Hi,

this happens when trying to connect to my (own) nextcloud instance.
It also happens when clicking the "Test or discover settings" in the configuration manager.
CalDav works on the server, at least syncing to android works without any issues.

Im grateful for any assistance you can provide.

CalDavSynchronizer.DataAccess.WebDavClientException: An error occurred while sending the request. ---> System.Net.Http.HttpRequestException: An error occurred while sending the request. ---> System.Net.WebException: The server committed a protocol violation. Section=ResponseHeader Detail=CR must be followed by LF
   at System.Net.HttpWebRequest.EndGetResponse(IAsyncResult asyncResult)
   at System.Net.Http.HttpClientHandler.GetResponseCallback(IAsyncResult ar)
   --- End of inner exception stack trace ---
   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 inner exception stack trace ---
   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()

Originally created by @Hafnernuss on GitHub (Jun 14, 2022). Original GitHub issue: https://github.com/aluxnimm/outlookcaldavsynchronizer/issues/360 Hi, this happens when trying to connect to my (own) nextcloud instance. It also happens when clicking the "Test or discover settings" in the configuration manager. CalDav works on the server, at least syncing to android works without any issues. Im grateful for any assistance you can provide. ``` CalDavSynchronizer.DataAccess.WebDavClientException: An error occurred while sending the request. ---> System.Net.Http.HttpRequestException: An error occurred while sending the request. ---> System.Net.WebException: The server committed a protocol violation. Section=ResponseHeader Detail=CR must be followed by LF at System.Net.HttpWebRequest.EndGetResponse(IAsyncResult asyncResult) at System.Net.Http.HttpClientHandler.GetResponseCallback(IAsyncResult ar) --- End of inner exception stack trace --- 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 inner exception stack trace --- 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() ```

kerem closed this issue

2026-03-01 17:41:43 +03:00

kerem commented

2026-03-01 17:41:43 +03:00

Author

Owner

@aluxnimm commented on GitHub (Jun 24, 2022):

The server sends invalid headers. Enable the general option Enable useUnsafeHeaderParsing.

@aluxnimm commented on GitHub (Jun 24, 2022): The server sends invalid headers. Enable the general option Enable useUnsafeHeaderParsing.