Express Document Update was Terminated by "...."

Hi,

Some of my users are having the above problem, when i checked in transaction code st22, it shows Runtime Errors: PERFORM_NOT_FOUND

Except: CX_SY_DYN_CALL_ILLEGAL_FORM

Users are using VA01,VA02 when having this problem.

Anyone with similar problem? May i know how to solve it?

regards,

zl