Downgrade/Original Script

Hi guys, i have someone questions:
1) Can i do a downgrade in the game? (the story is loooong, but simplifying: i upgraded 1 script, then i remove them, then i tried to put a script version 0.1.20, but the launcher says 0.1.21, and the script is 0.1.20 D: i pressed play and i got an error (bad actuallization))
2) If i remove script, and then i open launcher and click the game fix icon, the launcher will download the script upgraded?

Thanks, im waiting ours answers the most fast as possible

i think if you click the game fix, you don't need to remove the upgraded script. the game fixer update all files to actual version