Hi,nSorry for the late reply. The email somehow went to my junk mailbox.nI deleted the source part, it still gives me the same error when I tried to run.nI also tried setting the C_UDMI as a constant. It didn't report error. I assume it has something to do with Fluent cannot retrieve the some values of pt[1]. But I do need to read a the value of the specific phase in mixture that's why I used pt[1].nAny idea?.And thank you for your help!n