Error - Cannot map user while opening work item in SAP Inbox

Hi Folks,

There is a weird error coming up while a user of my client is trying to open a work item in his SAP Inbox. As soon as he click on work item , an error comes up saying that 'Cannot map user <USERA>'.

These work items have been forwarded to user B( who is facing this error) from USER A's Inbox by user C.

Any idea why this error is coming up.

Message number is /ORS/000007_SCR026. Even google is not helping much and open text guy also has no knowledge about it.

Any guidance is really appreciated.

Thanks in advance.

Regards,

Richa