Hello,
I implmented, almost verbatim, the sample file upload and progress manager as described in your getting started document.
http://www.telerik.com/help/aspnet-ajax/upload_gettingstarted.html
The first couple uploads when running through Cassini were successful. However subsequent uploads result in UploadedFiles.Count == 0, when I break into the code and check the InvalidFiles.Count it shows a count of 1, files that I uploaded just a few minutes ago will no longer upload. Sometimes if I navigate to a new folder I have not uploaded from and pick a small text file it will upload, but larger files (anything over a few K) fail. I had modified my web.config to increase the maxrequestlength and requestLengthDiskThreshold both to 512000 and execution timeout to 7200.
I am using the controls inside of DNN 4.9. There is no ajax being implemented in the module, there is no url rewriting being done, and there is no file extension validation being done.
I verified that the progress handler was correctly registered and the progress manager does run for large files but they never save to my target folder. I also checked the following document and did not find a resolution.
http://www.telerik.com/help/aspnet-ajax/upload_troubleshootingnofiles.html
Thank you.