ERROR: "IDOC_ADAPTER" / "ATTRIBUTE_IDOC_METADATA"

Dear SAP experts,

Good day!

Can i seek your advise regarding the error i am getting in sxmb_moni?

It seems that XI cannot deliver the IDoc to SAP system (in our case, Q40011).

We are in GDA (Acceptance).

The error log is,

<?xml version="1.0" encoding="UTF-8" standalone="yes" ?>

- <!-- Call Adapter

-->

- http://sap.com/xi/XI/Message/30" xmlns:SOAP=" http://schemas.xmlsoap.org/soap/envelope/" SOAP:mustUnderstand="">

<SAP:Category>XIAdapter</SAP:Category>

<SAP:Code area="IDOC_ADAPTER">ATTRIBUTE_IDOC_METADATA</SAP:Code>

<SAP:P1>Transaction IDX1: Port SAPQ40, client , RFC destination contain errors</SAP:P1>

<SAP:P2 />

<SAP:P3 />

<SAP:P4 />

<SAP:AdditionalText />

<SAP:ApplicationFaultMessage namespace="" />

<SAP:Stack>Error: Transaction IDX1: Port SAPQ40, client , RFC destination contain errors</SAP:Stack>

<SAP:Retry>M</SAP:Retry>

</SAP:Error>

The user SAPXI0RFC have already been unlocked in Q40011.

But, when i've checked the monitoring now, it is still error.

Kindly advise regarding my issue.

Thank you very much!

Fred