The windows file history can stop silently (!!!) with the event 201. Some people assume that is caused because of non-ascii chars or to long path names. But I liked to know exactly what causes the problem.
I tested 2 days and now I found the reason. If you have a file named "tesst" and another file called "teßt" (Eszett) in the same folder then the file history does not work anymore:
Maybe some of the moderators can forward this bug to the responsible Microsoft department?
This bug is not present for files like "tést" and "test". But its maybe with other special chars in different Windows Language Versions (I use German). All tests I did:
Bob found the same bug with an "underlined N":
"I was getting Event ID 201: "Unable to scan user libraries for changes and perform backup of modified files for configuration" until I finally narrowed it down to a file that had a bad filename. The filename had an underlined n. I don't know how a filename can have or get an underlined letter."