Error in Gantry

The PHP version is no problem, I test on PHP 7.2 too.
But the modules use different mb_... functions so mbstring is required.

I agree with you. The problem is that my host provider does not allow to enable that module with the 7.2 version of PHP. That's why i resolved my problem with that solution of reverting to 7.1. Thank you for testing. I didn't have the time to do that.