Pro Tools does not support audio file names that contain the following ASCII characters:
When opening sessions that contain audio files with illegal characters, Pro Tools automatically creates a renamed copy of each file (replacing these characters with an underscore “_”). Renamed files are copied to the Renamed Audio Files folder. The original files are left intact in the Audio Files folder.
Before the session opens, you are prompted to save a detailed report of the renamed files and their original file names to a Notes text file. Follow the on-screen instructions. By default, the Notes text file is saved to the Session folder.