Update to 8.0 or 8.1 - problem

Update to 8.0 or 8.1 - problem

My joomla version is Joomla! 3.10.11 and plugin EF4 Joomla-Monster Framework 4.9.6, php 7.4.
I change php to version 8.1. After the change, on the front page a message appears:

0
Call to undefined function CReatE_FunCTIoN()
PLG_SYSTEM_JMFRAMEWORK_JERROR_PAGE_DOESNT_EXIST
PLG_SYSTEM_JMFRAMEWORK_JERROR_GO_BACK_OR_HEAD_OVER
PLG_SYSTEM_JMFRAMEWORK_JERROR_BACK PLG_SYSTEM_JMFRAMEWORK_JERROR_HOME_PAGE

Please help