Okay, I don't know how things work with the editor and/or the save data when using
Save Data Manager; but having an almost brand-new save file helps to avoid data corruption.
I followed all the steps for my old save, and I just gave myself 1,000 Diamonds (just testing, y'know
). Got my save corrupted.
Fortunately, I didn't had much progress, so I just restarted with not much regret.
I decided to try again, giving myself 1,000 Diamonds and 10,000P; and it loaded with no problem!
Just to be clear,
this can be done with Save Data Manager on Rumble World version 1.1 in Ironhax/Tubehax/similarhax, but it really depends on your save data. BE SURE TO BACKUP YOUR SAVE IF ALL GOES WRONG.