Issue Description:
When attempting to run a .umod file, it does nothing or asks me with what program to open the file.
Solution #1 - Register .umod Files as Nerf Install Files:
Download and run the files found in the Nerf .umod Registration Fix.
Additional Notes:
This fix might cause conflicts with other Unreal engine games that use .umod files to install content. The conflict may be as small as an incorrect image for the game when installing or even installing to the wrong game entirely. Note that most .umod files have been phased out of Nerf ArenaBlast in favor of the Community Pack, and even if you can't run Nerf-specific .umod files, you may not ever need to fix it.