I have a page that uses multiple UpdatePanels and a MasterPage. Upon switching my AppPool to run in .NET 4.0 (Integrated Mode) from .NET 2.0 (Integrated Mode), I get the age old exception on the SECOND AJAX request my page makes (the first one works fine, the second request generates the exception):
Error: Sys.WebForms.PageRequestManagerParserErrorException: The
message received from the server could not be parsed. Common causes for this
error are when the response is modified by calls to Response.Write(), response
filters, HttpModules, or server trace is enabled.
Details: Error parsing near '
Just to be clear, the ONLY thing I have to change to fix/break the page is switching the app pool from .NET 2.0 to .NET 4.0.
NOTE: I’m not doing any of the normal things that can cause this error (Response.Write, Redirect, Tracing, etc.)…so that’s not the problem.
I’m bashing my head against the wall here…any help would be appreciated.
Try firing up fiddler and see what the difference between the two ajax calls is. At least the response part.