Nexclout Client: "Could not open file" when computing MD5

Nextcloud client: Nextcloud Desktop-Client 3.13.0 on Windows 11
Nextcloud server: Magenta managed service (

Running Nexcloud I get such errors whenever a new file is created in a folder:

[ info nextcloud.sync.checksums C:\Users\User\AppData\Local\Temp\windows-22489\client-building\desktop\src\common\checksums.cpp:204 ]:	Computing "MD5" checksum of "C:/Users/Loser/Nextcloud/#INBOX/In/test.txt.bc" in a thread
[ warning nextcloud.common.checksumcalculator C:\Users\User\AppData\Local\Temp\windows-22489\client-building\desktop\src\common\checksumcalculator.cpp:91 ]:	Could not open file "C:/Users/Loser/Nextcloud/#INBOX/In/test.txt.bc" for reading to compute a checksum "Der Prozess kann nicht auf die Datei zugreifen, da sie von einem anderen Prozess verwendet wird."
[ info nextcloud.sync.propagator.bulkupload C:\Users\User\AppData\Local\Temp\windows-22489\client-building\desktop\src\libsync\bulkpropagatorjob.cpp:189 ]:	"/#INBOX/In/test.txt.bc" transmission checksum "" "C:/Users/Loser/Nextcloud/#INBOX/In/test.txt.bc"
[ info nextcloud.sync.accessmanager C:\Users\User\AppData\Local\Temp\windows-22489\client-building\desktop\src\libsync\accessmanager.cpp:78 ]:	4 "" "" has X-Request-ID "dca5073a-f566-4a7d-824e-bbcb95a8ba3a"
[ info nextcloud.sync.networkjob C:\Users\User\AppData\Local\Temp\windows-22489\client-building\desktop\src\libsync\abstractnetworkjob.cpp:363 ]:	OCC::PutMultiFileJob created for "" + "" "OCC::BulkPropagatorJob"
[ info C:\Users\User\AppData\Local\Temp\windows-22489\client-building\desktop\src\libsync\owncloudpropagator.cpp:1588 ]:	scheduleSelfOrChild OCC::PropagatorJob::Running pending uploads 0 subjobs state OCC::PropagatorJob::Running
[ warning nextcloud.sync.networkjob C:\Users\User\AppData\Local\Temp\windows-22489\client-building\desktop\src\libsync\abstractnetworkjob.cpp:221 ]:	QNetworkReply::ProtocolInvalidOperationError "Server hat \"400 Bad Request\" auf \"POST\" geantwortet" QVariant(int, 400)
[ warning nextcloud.sync.credentials.webflow C:\Users\User\AppData\Local\Temp\windows-22489\client-building\desktop\src\gui\creds\webflowcredentials.cpp:208 ]:	QNetworkReply::ProtocolInvalidOperationError
[ warning nextcloud.sync.credentials.webflow C:\Users\User\AppData\Local\Temp\windows-22489\client-building\desktop\src\gui\creds\webflowcredentials.cpp:209 ]:	"Error transferring - server replied: Bad Request"

This happens with each new file and was present in former versions of NC client as well. Well, this is a temporary phenomenon - with the next sync iteration, the file is successfully synced. But it is more than annoying, since syncing doesn’t run smooth.

Note: the related folder is encrypted by Boxcryptor. But basically this is a pretty common file access conflict which might occur with any other application e.g. malware scanner in the middle.

I could imagine to make this more graceful by adding a delay between discovery and MD5 calculation, but not aware of such a configuration option.

Any ideas?

Really no ideas?

sounds like the File is locked - AV tools often do this as long the scan lasts

Yes, exactly! Isn‘t there any way to make the sync more graceful/less aggressive e.g. setting a delay, trigger sync in time intervals rather than on file changes, … Cannot find a config option which would solve such. This is so annoying since error messages pop up for each and every file change.

I don’t think this is common - don’t recall such reports till now. I would recommend opening support ticket at magentacloud - with their user base they will have best connections to the dev team.