This happened in our Prod environment a few months ago. We found that the IE version was an ongoing issue. There was a box under Tools>Internet Options>Advanced tabs for Enable XMLHHTP Support that needed to be checked. Forms then began to once again pull information when using the Inquire function.
Our users have since upgraded to IE 11 and have moved to a 64bit Windows OS.
Now in Test, PO20 is doing the same thing, but the XMLHPPT Enable Support box is checked.
Has anyone else had this problem, and if so, any set of magic steps to make it stop??