You try to publish an InfoPath form and get the following error:
The publish operation could not be completed. It cannot be determined if the form template was successfully published. Try publishing the form template again, or change the list settings to use the default sharepoint form. The SOAP message cannot be passed.
This error usually occurs when you have a large number of items in your list and the request is getting timed-out by IIS.
This problem can be fixed by increasing the time-out in the web.config of your SharePoint IIS site. Note that you will have to perform the same update on all your web front ends for each of the web applications that have the error. Add the bold part in the above code snippet, this will set the time out to 600 seconds, or 10 minutes.
<trustLevel name="WSS_Medium" policyFile="C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\14\config\wss_mediumtrust.config" />
<trustLevel name="WSS_Minimal" policyFile="C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\14\config\wss_minimaltrust.config" />
<trustLevel name="WSS_Custom" policyFile="C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\14\config\wss_custom_wss_minimaltrust.config" />
<customErrors mode="On" />
<httpRuntime maxRequestLength="51200" executionTimeout="600" />
<authentication mode="Windows" />