"Unable to read header from archive file: " -> i guess you have a corrupted download.
Please try to re-download it.
Viewing post in new version wont run on ubuntu
downloaded again and made sure it downloaded correctly. its acting the same as last time
thatgamer@thatgamerscustombuild:~$ '/home/thatgamer/Desktop/3DNes_Linux_V1.4.0/3DNes.x86_64'
Found path: /home/thatgamer/Desktop/3DNes_Linux_V1.4.0/3DNes.x86_64
Mono path[0] = '/home/thatgamer/Desktop/3DNes_Linux_V1.4.0/3DNes_Data/Managed'
Mono path[1] = '/home/thatgamer/Desktop/3DNes_Linux_V1.4.0/3DNes_Data/Mono'
Mono config path = '/home/thatgamer/Desktop/3DNes_Linux_V1.4.0/3DNes_Data/Mono/etc'
Preloaded 'ScreenSelector.so'
Preloaded 'libopenvr_api.so'
Preloaded 'libzipw.so'
Player data archive not found at `/home/thatgamer/Desktop/3DNes_Linux_V1.4.0/3DNes_Data/data.unity3d`, using local filesystemthatgamer@thatgamerscustombuild:~$