Batch Find and Replace

When I try Batch Find and Replace, I get a msg like this: 

The operation failed.

Error: File 'C:\Users\olbec\OneDrive\Documents\Amplexor\2017\R-0462-17 KXRde-da\New folder\R-0462-17 KXR-Objekte KR C V8.5 WO446727 de-da\da-DK\FROM_NXPS\T-00c078c5-6d8b-4676-b74e-45bdabcf4d4e.xml.sdlxliff' not found.

Now, I know why: The app creates a back-up file at random and then the original file is disappearing. Why does the app create backups when its unchecked in the app.