Dear Indira,
If you have not installed PI in your system then the AEX usage type is wrongly used since it should be user for PI Java only installations.
Please take a look at SAP Note 1435267 on how to avoid this errors in the logs and change the usage type.
XPI = "Classic" PI installation with dual-stack server (ABAP+Java)
CE = Standalone ESR for CE (Java only)
AEX = Lean Integration Broker (Java only; since 7.30)
Check SAP Note 2217231 if it's applicable in your system.
Best regards,
Mate