I came across this one recently, basically after successfully provisioning PWA on a new Windows 2008 R2 server I then found that I received the following errors in Resource Center and when editing items such as Users:
“There was an error loading the page. Please try again by clicking Refresh. If this problem persists, contact your administrator.”
“An error was encountered in loading the page. Refresh the page, or contact your server administrator if this problem persists.”
This led me to increase ULS logging to Verbose and eventually find this little one:
Application error when access /_vti_bin/PSI/resource.asmx, Error=’gzip’ is not a supported encoding name. Parameter name: name at System.Globalization.EncodingTable.internalGetCodePageFromName(String name) at System.Globalization.EncodingTable.GetCodePageFromName(String name) at System.Text.Encoding.GetEncoding(String name) at Microsoft.Office.Project.Server.PSIForwarderHandler.ProcessRequest(HttpContext context) at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)
It seems some settings were different in this installation (this was a clean install by clearly not default), see the IIS Compression settings (Open IIS Manager and select the Compression setting under the server name):
Once I deselected ‘Enable dynamic content compression’ and hit Apply then immediately the above errors disappeared!
UPDATE:
Came across the following KB article which covers this issue for IIS6: http://support.microsoft.com/kb/947899