I was working with an asp.net applcation and one of the pages was producing errors. After going through the error, I realise it was failing with a timeout error. So, I went ahead and increased the timeout value for both WCF service and also the SqlCommand that's being called by the Wcf service, however, even though there was no exception, the data was not displaying on the site.
So, to test the issue, I started inspecting the issue in Chrome and under the Network tab, there was an error "Sys.WebForms.PageRequestManagerTimeoutException", which meant some kind of error with the UpdatePanel. After this, I increased the timeout value for the UpdatePanel by setting the "AsyncPostBackTimeout" property on "ScriptManager" and then it got fixed.