A Sys.WebForms.PageRequestManagerParserErrorException error is thrown sporadically on some demos in the QSF.


Steps to reproduce:
(The error is not reproducible every time on all machines so you can find attached a fiddler cap log from the reproduction):

1. Open http://demos.telerik.com/aspnet-ajax/imageeditor/examples/overview/defaultcs.aspx

2. Try to open the Crop dialog (in IE11)

Result: A script exception is thrown
SCRIPT5022: 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 'HwdlHwoCAh8LaB8MaGRk'.
File: Telerik.Web.UI.WebResource.axd, Line: 15, Column: 16485