After migrating from Wildfly-8.2.0 to Wildfly-16.0.0, my JEE application launched normally and
displayed expected data read from (PostgreSql) database, but neither of the (insert/update/delete)
operations is saving to database (with no exception fired) !
I redeployed the same application on the old version of Wildfly and (insert/update/delete) operations worked.
What was missing is to add the "eclipselink.jar" file in
"wildfly\modules\system\layers\base\org\eclipse\persistence\main"
and reference it as a "resource-root" in
"wildfly\modules\system\layers\base\org\eclipse\persistence\main\module.xml"
Unfortunatelly, no exception was fired describing the missing configuration of eclipselink!