Webdav and Office 365

Hello Community,

We have following strange situation:
Hardware is a windows 8 laptop, also installed is Office 365. cryptomator version 1.5.16 (exe-2831.223)

A Cryptomator fault resides on an USB stick. Opening the fault, and copying and deleting data within the fault using windows explorer has no problems.

When using double-click to open an Excel file which resides in the fault, Excel starts and tells me:
“The network is not available or not started, please check the network connection.”
and does not open the file.

This behaviour can only been seen when no network connection is available
But: when I try to create a new excel file (also without network connection) I can store it into the fault and can reopen it without problems.

What I tried then, is to connect a simple network-switch to the laptop (with no other devices connected to the switch, meaning no internet, no IP address received, simply an empty switch and a cable)

In this case the same excel file can be opened and closed without problems. When I disconnect the switch right afterwards again, the file can be opened again without problems.
Next I renamed the file - and now it cannot be opend, given the same error message.

Besides, I can see this behavoiur only within subdirectories of the fault, when the file is located in the root, then it can be opened everytime, also without network connection.

To my opinion this has to do with some authentication problems with wedav, as the fault is connected via webdav and a drive letter is assigned to this connection.-
(it can be seen in explorer as (\cryptomator-fault@42427\DavWWWRoot\somecode) (U:)

Is there anyone who has a solution?
kr, michael

Is there anybody whith an idea about this problem?

Despite the fact that Windows 8 is pretty outdated, have you tried using FUSE/WinFSP instead of WebDAV? (If WinFSP is even running on such old OS)