ERROR org.cryptomator.ui.controllers.UnlockedController - Mount failed

When I try to mount my vault with cryptomator v1.3.2 on Debian Jessie amd64. I get:

08:59:15.733 [pool-3-thread-2] INFO org.cryptomator.frontend.webdav.servlet.WebDavServletController - WebDavServlet started: /7CPTV5OES4O6/VAULT_mator
08:59:15.839 [pool-3-thread-2] INFO org.cryptomator.frontend.webdav.servlet.WebDavServletController - Mounting http://localhost:42427/7CPTV5OES4O6/VAULT_mator using org.cryptomator.frontend.webdav.mount.Lin
uxGvfsMounter
08:59:15.845 [JavaFX Application Thread] ERROR org.cryptomator.ui.controllers.UnlockedController - Mount failed.
org.cryptomator.frontend.webdav.mount.Mounter$CommandFailedException: Command failed with exit code 2. Expected 0. Stderr: Error mounting location: volume doesn’t implement mount

    at org.cryptomator.frontend.webdav.mount.ProcessUtil.assertExitValue(ProcessUtil.java:28)
    at org.cryptomator.frontend.webdav.mount.LinuxGvfsMounter.mount(LinuxGvfsMounter.java:39)
    at org.cryptomator.frontend.webdav.servlet.WebDavServletController.mount(WebDavServletController.java:102)
    at org.cryptomator.ui.model.Vault.mount(Vault.java:140)
    at org.cryptomator.ui.controllers.UnlockedController.lambda$mountVault$1(UnlockedController.java:164)
    at org.cryptomator.ui.util.AsyncTaskService.lambda$asyncTaskOf$0(AsyncTaskService.java:43)
    at org.cryptomator.ui.util.AsyncTaskService$AsyncTaskImpl.lambda$null$6(AsyncTaskService.java:106)
    at org.cryptomator.ui.util.AsyncTaskService.logExceptions(AsyncTaskService.java:135)
    at org.cryptomator.ui.util.AsyncTaskService.access$100(AsyncTaskService.java:24)
    at org.cryptomator.ui.util.AsyncTaskService$AsyncTaskImpl.lambda$run$7(AsyncTaskService.java:104)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
    at java.lang.Thread.run(Thread.java:748)

===
mount http://localhost:42427/7CPTV5OES4O6/VAULT_mator ~/VAULT/
mount: only root can do that

As noted, the mount command is successful as root and I can access the files within.

What can I do?