Hey,
kindly ask for update to 1.38.1 maintenance release (1.38.0 was ok)
# php maintenance/update.php
PHP Fatal error: Uncaught ExtensionDependencyError: Diagrams is not compatible with the current MediaWiki core (version 1.38.1), it requires: >= 1.34.0, <= 1.38.
Hey, kindly ask for update to 1.38.1 maintenance release (1.38.0 was ok)
Regards