I have THE SOLUTION for retroarch issue. I had tested a while ago. If you have installed any version after the 1.7.7 (32 bit), you have to RESET completely your Shield Tv for fix. I tried now and the fix is ok. You are not able to install a newer version in 32 bit or to downgrade to 32 bit. probably remain certain files that are unable to config correctly retroarch. I repeat, the ONLY solution is to reset completely tour shield tested now for me and I'm very happy.