I had the same problem, when i restore the filed & add it to the white list, the file was "corrupted" and the update download would stop at 86% i think.
I tried to go into the folder you quoted to delete the crashreporter.exe.download, it said to me i did not had the permission to do that. Even with GoG close or computer rebooted.
I had to restart in safe mode (seek through google on how to restart in safe mode if needed for Windows 10), in safe mode i manage to delete the file, rebooted, download restarted and completed this time.
I don't know who is to blame, maybe bitdefender for not restoring the file properly with full permission access (even if they were all ticked on Windows)