Message Viewer Response XML tab is blank

Not sure what is going on here. We have a parameterized request xml. When we run the test case, the test steps all run fine and show up in the test case log. However, when I double click on the test case log entry, I am getting a Progress screen while it loads the wsdl definition (was not doing this before) and then when the message viewer opens, the request message xml tab is blank (so if the response message xml tab). The request message raw tab is populated and formatted nicely. The response message raw tab does contain the response, in one long line and not formatted at all.

This was working fine before, so I'm not sure what I changed. I expect the response to be there and be formatted. I was not getting the "loading definition" window previously. Any ideas on what I can check?

Thanks,

Joanne