Please check whether the path specified in the BPM Studio is correct. It is possible that the object you are looking for is no longer found in its original location.
You can also open the archive files with a text editor and see what the original path was.
E.g. open via "C: \ Users \ [YourName] \ AppData \ Roaming \ AlcaTech \ BPM-Studio Profi" the respective playlist with the ending .lst with a text editor such as Notepad. There you will find the paths of the files as they are stored in the database. Then copy the complete path including the file name from one line to the clipboard.
Track0 = H: RUMPELECKE14 - BARRY MANILOW - COPACABANA (AT THE COPA) .MP3
Mark from "H:" up to and including ".MP3"
Then please go to Start / Run and insert this path there. Then you hit enter.
The standard player should now open and play the file. If that does not work, the path or the access authorization is incorrect.