Torrent Pro app is very stable, so crashing of the app is a rare thing. However, if you face a crash and are unable to open the app, then try to clear the app data in your phone settings or reinstall the app. Don’t worry about your existing partial downloads. Once you reinstall the app, you can add the same torrent link/file to the app and it will automatically recheck for the existing file and continue the download from there (make sure you select the same download location).
Rebooting your device may also help. If you still face issues, please contact us.