Null or Default Application Task

Call.attributed() JTAPICallContact[id=0,implId=6937/1,state=STATE_ATTRIBUTED_IDX,inbound=true,App name=null,task=null,session=21000000001,seq

If APP_MGR debugs are enabled we may notice that the default task is loaded as the correct task could not be loaded
MIVR-APP_MGR-7-DFLT_TASK_INIT:Default application task initializing: Application=null,Application
MIVR-APP_MGR-7-DFLT_TASK_STARTING:Default application task starting: Application=null,Application
MIVR-APP_MGR-7-DFLT_TASK_ENDED:Default application task ended: Application=null,
MIVR-APP_MGR-7-ABORTING_CONTACT:Aborting contact: Application=null,Task id=22000000025,Contact id=19,Contact

This may have been due to some error reading DB to initialize the Route point
MIVR-SS_TEL-3-UNABLE_LOAD_APP:Unable to load Application: Application=icd,Failure reason=fails to get application from app manager,Route Address=5100,Application Id=null,Exception=com.cisco.app.InvalidApplicationException: failed to load configuration; nested exception is:
MIVR-SS_TEL-3-UNABLE_LOAD_APP:Unable to load Application: Application=153icd_rg1,Failure reason=fails to get application from app manager,Route Address=1072,Application Id=null,Exception=com.cisco.app.InvalidApplicationException: failed to load configuration; nested exception is: com.cisco.config.ConfigException: DB_ACCESS_ERROR; nested exception is: com.cisco.database.DBNotReadyException: Database Manager-CRS Config Datastore is not IN_SERVICE for getConnection

Data resync should fix this issue.
Engine restart can also fix this issue
If the issue is not fixed or to understand the cause for failure to load the application the first time, this can be escalated to Unified CCX Engine/DB team.