You need to be on DEX to run most SPRX scripts. The EBOOT is what calls on the SPRX script. If I were you I'd convert to DEX and if you're wanting to mod GTA then I'd suggest converting to BLES as well (if you're not already on it)
Convert CEX to DEX:
Convert GTA from BLUS to BLES:
Please refrain from posting links to other sites, thanks.