Renaming Extension

For some reason Hazel renamed every .3gp file I have to a .3gp-1, .3gp-2 and so on. How do I make a rule to rename the extension when the number extension changes on every file by number (1,2,3...ect) Thank in advance for your help, I know their is a solution, I'm just new to Hazel and it's been an amazing too.

Rename it to what? Usually the -1, -2 is tagged on when the original exists. Also, it's probably better if you look into what's causing it. I suspect you have a rule set up to do that, possibly running over and over again. You should check the logs to find that out.