Error in Gantry

Hi there. I'm renewing my site with the Gantry Framework and the Helium theme. I have used the JEM + Gantry before without any problems. But now i have a strange problem. When i put any JEM module on the home page it just give a blank page with the word "Error" on the top left and nothing more. If i deactivate the module, the page works fine. Does anybody else have this problem? Joomla 3, gantry, and JEM are in latest versions.

Please try with an official joomla template. Normally on this there is no problem.

Problem solved. My PHP version was in 7.2 and the mbstring function was not avaible. Changed to 7.1, and the problem disappeared.
Thank you. Maybe this could be usefull to somebody else.
Greetings from Portugal, i'm helping in the portuguese translation. Keep up!

sorry asking again: was this just on JEM 2.2.3?

Yes. In version 2.2.3 and joomla 3.8.5. It wasn't a problem of JEM but from the Gantry Framework.

Thanks for the info Pauojcd!

Our demo site is on Gantry as well.... so it's good to know