This is a PHP Setting that the Test Script is warning you about; your web host would likely have to update for you, unless you can edit values in your PHP.ini through your cPanel. The UBBDev slug about this is available at UBB.threads System Requirements Test · Wiki - PHP Max Input Vars

You can read about this issue Issues with the PHP 'max_input_vars' Setting · Article

In short the more forums you have the more variables your configuration update will hold when you update the control panel, after the default 2000 is overtaken (I think about 20 some odd forums) it won't submit a complete set of variables.

I am a Web Development Contractor, I do not work for UBBCentral. I have provided free User to User Support since the beginning of these support forums.
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