Cannot lock a vault

Crytomator runs fine on my openSUSE Leap 15.1 machine, however I cannot lock a vault. This is for Vaults created on NFS disks but also on local (ext4) disks.

When I try to lock a vault it asks me if a forced lock should be executed since there might be other programs using the Vault. However thatś not the case.

Is this a know bug? Or is there anything I can do to make enable Vault locking>

Environment I use: openSUSE Leap 15.1 downloaded and installed cryptomator-1.4.15-x86_64.AppImage from the website. The AppImaged is appimaged-9~pre.1495805837.d05eac1-lp151.2.2.x86_64 and comes for the official openSUSE Leap 15.1 repos.