... I also got an error "Cannot rename the recorded file."
Your problem is different. The file you are trying to play back is not there.
Three possible reasons:
You didn't tell Boldbeast the right folder in which your recordings were saved.
Please click the "App Settings > Clip Saving Folder" option in the app, choose the folder in which your recordings were saved, then you can play back them in the Call List screen inside Boldbeast. If you are running Android 11 up, you should first change "App Settings > Clip Saving Drive" to SAF (Storage Access Framework).
You previously changed the folder, as a result some recordings were in the old folder some recordings were in the new folder. In this case please open the Call List screen in the app, click Move Files to move all recordings from the old folder into the new folder.
Now all recordings are in the new folder, you can play back them in the Call List screen inside Boldbeast.
You have deleted your recordings using a file manager out of Boldbeast, so the sound files were gone but file entries are still displayed. In this case please open the Call List screen in the app, click Rebuild List to delete the entries, so that they will no longer be displayed.