Hi guys,
Everyone has come across this problem when modding certain pac files, the process below should fix the issue and should enable you to edit the matchup screens, main menu, arena select screen etc..
Extract the texture you wish to mod and make a copy of it.
Open the copied version in a Hex editor and replace the entire file with 0’s
Go back to the original image and mod as required and save as a lower DXT, for example the matchup screens are DXT5, Save these as DXT1 no alp