DraStic

I recently installed drastic on my new tablet and I was playing a mario kart rom on my micro SD card without any problems. A couple hours later I tried to load additional roms from my SD card and they didn't even show up. All of the roms were zip files so I figured extracting them might help. The extracted roms did show up - but they all gave me the "the file you tried to open is not a valid rom" error when I tried to start them. When I copy the roms over to the internal storage they load without a hitch. And oddly enough, the Mario kart rom still loads off the SD card, so only "new" roms I've yet to load on the SD card that don't work.

How can I fix this?

Device: Amazon fire HD 8 plus
Version: r2.5.2.2a

Edit: added another game to my rom directory, loaded up drastic and hit load game, and all of the roms that weren't showing up previously now show up and work - but the new rom I added doesn't appear in the list.

Edit 2: okay so restarting my tablet (twice) seemed to fix it. I imagine I'll have to do that every time I download more games - a little annoying but at least they show up eventually.

Hello. I have the same problem with a Lenovo P11 Pro tablet, running Android 10.
Drastic runs fine from internal storage (with both .nds and compressed roms), but when i try from an external sd card, zipped roms are not listed and no .nds rom is playable anymore (same error message than in above message saying the rom is invalid).
The roms not working from external are the same ones that are working from internal.

Is it a problem with some Android devices with sd card slots ? A problem with recent Android versions ? Thanks for any info about this issue.

Try ejecting your SD card in software and then inserting it back again. I had that same problem and this helped me solve it.