Unable to mount a tresor on WIndows NTFS

Just FYI:

While I had the target mountpoint directory opened in Windows Explorer I got the following error when trying to mount a tresor:

org.cryptomator.common.vaults.Volume$VolumeException: Unable to mount Filesystem
	at org.cryptomator.common.vaults.DokanyVolume.mount(DokanyVolume.java:48)
	at org.cryptomator.common.vaults.Vault.unlock(Vault.java:151)
	at org.cryptomator.ui.unlock.UnlockWorkflow.attemptUnlock(UnlockWorkflow.java:100)
	at org.cryptomator.ui.unlock.UnlockWorkflow.call(UnlockWorkflow.java:81)
	at org.cryptomator.ui.unlock.UnlockWorkflow.call(UnlockWorkflow.java:44)
	at javafx.concurrent.Task$TaskCallable.call(Task.java:1425)
	at java.base/java.util.concurrent.FutureTask.run(Unknown Source)
	at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
	at java.base/java.util.concurrent.FutureTask.run(Unknown Source)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
	at java.base/java.lang.Thread.run(Unknown Source)
Caused by: org.cryptomator.frontend.dokany.DokanyMountFailedException: Error while mounting.
	at org.cryptomator.frontend.dokany.MountFactory.mount(MountFactory.java:130)
	at org.cryptomator.frontend.dokany.MountFactory.mount(MountFactory.java:116)
	at org.cryptomator.common.vaults.DokanyVolume.mount(DokanyVolume.java:43)
	... 11 more
Caused by: com.dokany.java.DokanyException: DokanMain returned error code-5: Dokan mount failed - Cannot assign a drive letter or mount point. Probably already used by another volume.
	at com.dokany.java.DokanyMount.lambda$mount$2(DokanyMount.java:98)
	... 1 more

Once I closed Explorer mounting the tresor worked fine.

Looks like viewing the mountpoint in Explorer somehow locks the target directory such that mounting a tresor is inhibited.

Welcome to the Cryptomator Community :slightly_smiling_face:

Yes, this is a known issue, see

Explorer keeps an open handle to the location, which prevents necessary changes of the directory node.