[Other] I can't open my rom in unnamed trainer editor

[Applausear]

It says "Unable to open rom" when I load my hackrom in Unnamed Trainer Editor

You can test, too.
https://www.dropbox.com/s/qd08o8ur72k8l9x/Pokemon - A pedra das Fadas - backup.ips?dl=1
Patch to a Clean Fire Red File

 

[Bobsomeness]

Try using G3T or HTE instead, I use those.

 

[Bakugo2op]

You probably had the selected gba rom file running.Turn off the rom file( probably advance map) and then use the program :/

 

[Momoro]

Sadly, the majority of ROM Hacking tools tend to be programmed in a strange way, (I don't want to say "wrong", because it's rude) so if you have PGE or Advance Map open while trying to do this, it won't let you because the program that is also open (Advance Map, PGE, etc.) hasn't closed the stream for reading/writing to the ROM File, because it wasn't programmed to.