I have a problem with running the second .exe which is inside EP Virtual Box. I tried everything possible and always this when I try to click on something where second exe is needed to run:

My main app is the Core (C#.NET) but I also made a second exe (must be second exe since it is written in C++) which decrypts and reads certain files.
Second app is a AES decryptor and reader which decrypts the data and passes it to the main app listview component.
I never used Virtual Box for .exe files, just .dll and multimedia so I am really at a stop. I cannot leave decrypt.exe outside.
Any help would be greatly appreciated.
