OMS.ear not starting up

we're trying the below steps after bringing down the domain:

import ordermgmt schema from an already stable environment having OSM 7.3.0.1.12 on it.

resolve the OM_$INSTALL$PLAN and OM_$INSTALL$PLAN_ACTIONS table differences, WL_LLR table differences

result was the admin server and managed servers were able to come up but the oms.ear is remaining in failed state or prepared state.

while trying to start it getting below erroe in the managed server logs

****************************************************************************************************************************************

Policy Name                                                 Health   Result Messages

----------------------------------------------------------- -------- ------ -----------------------------------------------------------

db_env_policy - Check database version & environment        CRITICAL Failed Info: Checks database version, database driver version,