there is a standard portlet by HP which is called "Request List". When I add some attachment fields I get a result and at some attachment fields I get an error message:
An unknown error has occurred. For more information, please contact your PPM administrator and provide the following GUID number: GUID=C19421FF-3B56-B65B-C416-F8D2FD13E668
In the screenshot I have two attachment fields. one of them is created in the Request Types and one of them in the Request Header Types. First I assumed it might be a problem because of Request Types or Request Header Types. But it wasn't it!
Do you have an idea why I get the error message?