Games won't load with Big Box through Steam Big Picture

[mdueck]

I am trying to use Big Box on my TV via my Steam Link's Big Picture mode.

I first tested all my controllers and games on my computer and they all work fine. I then added Big Box as a Non-Steam Game to my Steam library of games.

I can open up Big Box through Steam Big Picture mode (both on my PC and using the Steam Link/TV). I can also navigate around Big Box with my controllers at both locations. The problem arises when I try to load a game.

On my PC when I try to open an N64 game using Project 64 2.3.2.202 I get BB's "Now Loading..." screen then the game pops up and shows the opening 'Nintendo' screen for 1 second before I get BB's "Game Over" screen. However, PJ64 doesn't close, it stays open the the game loads but it is windowed and I can see BB in the background.

When I try to open the same game/emulator using Steam Link on my TV I get BB's "Now Loading..." screen then it shows PJ64's main window (all the ROMS I have in my directory) with this Error message in front:I then have to go to my PC and exit the emulator. BB and Big Picture are still running just fine though.

A workaround I've been using is, I connect my PC to my Steam Link, I then minimize Big Picture and open BB directly from a shortcut on my PC's desktop. This allows everything to work just fine. I am also using VirtualHere so my controllers don't require any special mapping when I plug them into my Steam Link. (Side note: I can also open BB through Steam and it works great, I just can't open it using Big Picture mode in any way)

Although I have been able to use BB on my Steam Link, it would be really nice to be able to actually play it through Big Picture so that I don't need to go into my desktop to open it. 

Has anyone else experienced this error? Am I using an outdated emulator?
Any help would be much appreciated, thanks!