File is locked by another application

Hello,

one of our customers has an error with locked files inside M-Files. There are Excel files located in traditional folders. These Excel files are linked with power queries. 
If a user wants to open one of these files, sometimes a message appears that this file is locked by another application. But there is no application which has locked this file.

Is it possible to load these files directly into M-Files and update the power queries for the links to the other files with a path, which refers to the corresponding object inside M-Files containing the needed Excel file?

I don't know, how I can solve this problem. 

Greetings from germany

Michael