I changed format and it does not work

I'm sorry but I can't understand you. Could you please be more informative and write more clear. 

What is "saterproof"? What "format" you've changed? Where and on what are you doing something?

if you want to reset all options, please navigate to Dashboard > Plugins admin page, find Forum - wpForo and click on Uninstall button. Please not, this will delete all forums, topics and posts too. So if you don't have any important information you can use this. After uninstall, click on activate button and all will be reset and installed as initial wpForo.