@mitu So, It appears that doing an update recreates the folder I was missing. It took a long time to update but that is because it was from source for many packages it appears.

I did an image install on a spare SD card and copied the ROMS folder to an external drive as a backup of the folder structure. Just in case I need to refer to it again.

Thanks for the help and suggestions.
BC

@ruicunha I am assuming you are referring to MAME? And rebuilding using Clrmamepro? If so, then you dont have to rebuild a whole romset you can rebuild a smaller subset if you wish.

@MWGemini
For my Pi Zero's I have a couple of the Anker 2-4-port USB wall chargers around the house. They output up to 2.1 amps (might be 2.4) per channel, and I've switched everything over to Amazon Basics micro USB cables which seem very nice. The power supply/cables hopefully aren't the problem as they power all the other working Zero's I have just fine.

@BuZz
I have another topic open about getting my ethernet adapter working since my 2.4ghz wireless has been flaky. Will RetroPie (like version 4.0.2. or maybe 4.1.0) give me a warning if it fails to compile or update something like EmulationStation for example? I know you mentioned RetroPie was JUST updated to NOT clear error messages for better troubleshooting.

I'm wondering because I'm now actually watching my other Pi (not this one I'm having problems with) run all the updates and I don't think I've ever seen that much code flash across the terminal window on the ones which have had issues (it's up to like 15+ pages of code, and it's been doing the update for maybe an hour so far and I don't know how much longer it has to go). I can never remember the problematic ones taking longer than maybe 20-30 minutes to update something which has me wondering if they're really failing to update, and I missed any error message which flashed up, and that's been why I could never fix them.

--once I'm done updating this working Pi Zero I'll see if the malfunctioning one can use the Ethernet adapter (but I'm pretty sure only newer versions of RetroPie can use that ethernet adapter since I could never get it working before - so I might be stuck without internet access to test anything out on the malfunctioning Pi Zero).