Drive not mounted - system error 67

Installing Dokany does not change anything since you are using WebDAV as the unlocked vault provider. (; You can change this in the settings.

Otherwise, there are a ton of posts about Systemerror 67 regarding crpytomator:

My first suggestion is to check up the names and order of items in the registry keys of:
Computer\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\NetworkProvider\HwOrder
Computer\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\NetworkProvider\Order
Computer\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\NetworkProvider\ProviderOrder