Corrupt files after using officelibre

I am using officelibre for the first time due to Microsoft not recognising my office copy.
The Microsoft office is still on my pc.

It initially worked.

When i tried to access my files today on a usb stick the filenames have all been changed and I cannot access them.

Is it possible that Microsoft has changed these files to prevent their use with officelibre?

How can I restore these files.

Ive tried a disk check repair without success.

Possible, but very unlikely. Even, if they intended to do this it would be quite expensive in the US if they were caught on this.

Filenames change to what?
Random garbage like x4h87, chinese characters, or some message like “File1 access denied” or quaeantined.
.
Check on your security system preventing access, ransomware encrypting your files, an “encrypt my USB” for security system you bought with the stick (and of course, if you just have the right USB-stick).