Did you use the official 4.2 image from the site? Did you read about the info you should post? It's not requested just for the craic. Help us to help you...

@Kecha read the forum rules! Next infraction will result in a ban.

@TMNTturtlguy I am using a Sandisk 32 gb ultra, bought in the store. And I was trying to write my image back to this same card after a full format (first I wipe the Linus partition with a quick format in my Sony camera, then I do a full (overwrite) format , with 'format size adjustment' to On in sdformatter). It's really odd but there are more reports about this issue.
rpi-clone is a better alternative imo if you want to use the same size card (or smaller) for a back up

Apart from the fact that they then appear in both menus (which is what you are aiming for anyway), it should be fine. Also, don't forget if the rom requires a parent or bios set (like the Neo Geo stuff), you will need to symlink these files too.

I have a Pi 3 that I have just written the Retropie 4.2 image from the website on to and put a couple of SNES games on and I can confirm that using the default emulator (lr-snes9x2010) it works fine (I am using a wired Xbox360 controller). It sounds like a permissions error. How did you copy the roms on to the Pi?

@Spectreman I agree that the white screen bug is not fixed, however it has been improved immensely. The performance after the upgrade was significant, so I would consider it a major performance upgrade, but not necessarily a fix. More work still needs to be done for sure, but there are a lot of cool projects going on right now as well. You should be able to run trokyfran on a Pi3 with standard configs with 14 systems without an issue. I would again try to adjust your VRAM up or down in small amounts. Maybe 120 or 80 would work. You never shared what pi model you are running, power supply, do you have any modifications to your settings? Have you changed your gpu settings? Overclocked?

So I got it solved: it appears that the rights were different on the .rc file for AdvMame 3.x (it was owned by root and not pi) so I fixed that and copied over the input map entries from one of the earlier versions' .rc file and now everything appears to be working. :)

@pjft

Actually, they don't.

When I transfer via USB, the autocopy feature doesn't duplicate them. They only exist on the stick.

And when I do manual transfers in file manager (of bios or themes), I ignore them, so no sweat.

@edmaul69 great, please do and let me know how it goes!

This should remove all dithering effects that the emulator explicitly added - but obviously keeping any that the games had originally.

any luck with this?

having never used or tested the script, i can only give some random thoughts for your troubleshooting consideration:

did you try adding the script to crontab so it runs at boot time?

crontab -e
@reboot nohup ./home/pi/RetroPie/scripts/es-cec-input.py
(note there is a typo in the script comment "hohup")

double-check your locale & keyboard layout is correct:
Raspi-Config > Localisation Options > Localisation Options
Raspi-Config > Localisation Options > Change Keyboard Layout

i had some strange effect from my keyboard until i set these correctly
(en_US.UTF-8 / Generic Logitech Keyboard)

what is the remote make/model, and how is it connected?

should the vendor id/model match up with what is stored in?:
/etc/udev/rules.d/40-uinput.rules

make sure there are no unsupported keys mapped in /opt/retropie/configs/all/retroarch.cfg
https://github.com/dillbyrne/es-cec-input#supported-keyboard-keys

sorry if this wasn't very helpful, i'm just a measly end-user with not much experience

@pjft Thanks, but once again you were major help! You pointed me right to I needed to be and I just pushed a few buttons.

Solved! This is how you get Intellivision to work on 4.1 ! give @edmaul69 a thumbs up!

@meleu so....everything working it appears. I edited my SNES file and I missed the hot_key stuff so now I can exit my Emulators....thank you for the help.

I am having this problem too and its really frustrating!