Cryptomator (local vault) crashed but left drive letter assigned

On Windows 10.

This morning I found that my primary local vault was inaccessible to the file system–it had been working yesterday. Where Explorer had shown all the familiar folders, today it the same area was just blank.

After killing Cryptomator and restarting Windows Explorer (but not the computer) the drive letter I use for this vault/drive was still assigned (showing as “occupied” in Cryptomator). I’m able to unlock the vault by assigning it to a different letter but all of my links/shortcuts refer to the vault’s original letter/path.

I can reboot the computer to get back on track but I can’t have this happening: the file system needs to be utterly dependable. I assume the issue is the result of my having upgraded a few days ago to 1.5.5 / Mountain Duck 4—I never had a single problem with vault access before the upgrade. Also since the upgrade, Mountain Duck 4 has been unusable: it is unable to mount the volume at all, so I’m using Cryptomator to open it. (Backup high on my priority list but I have high priority deadlines today.)

So is there a known problem here, one that can be fixed and forgotten? Or should I revert to the old versions?


On Worg.cryptomator.common.vaults.Volume$VolumeException: Unable to mount Filesystem
at org.cryptomator.common.vaults.DokanyVolume.mount(DokanyVolume.java:57)
at org.cryptomator.common.vaults.Vault.unlock(Vault.java:129)
at org.cryptomator.ui.unlock.UnlockWorkflow.attemptUnlock(UnlockWorkflow.java:103)
at org.cryptomator.ui.unlock.UnlockWorkflow.call(UnlockWorkflow.java:80)
at org.cryptomator.ui.unlock.UnlockWorkflow.call(UnlockWorkflow.java:43)
at javafx.concurrent.Task$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.MountFailedException: java.lang.IllegalStateException: Mount failed: Cannot assign a drive letter or mount point. Probably already used by another volume.
at org.cryptomator.frontend.dokany.MountFactory.mount(MountFactory.java:128)
at org.cryptomator.common.vaults.DokanyVolume.mount(DokanyVolume.java:52)
… 11 more
Caused by: java.lang.IllegalStateException: Mount failed: Cannot assign a drive letter or mount point. Probably already used by another volume.
at com.dokany.java.DokanyDriver.start(DokanyDriver.java:72)
… 5 more