Interesting discovery yesterday that I thought I should share. After installing SharePoint 2010 Service pack 2 a customer ran into problems with their InfoPath forms. The generic error message was “The custom code in the form cannot be run. This functionality may be deactivated on the server”. Looking in the ULS log there were some more information:
Microsoft.SharePoint.UserCode.SPUserCodeSolutionProxiedException: Could not load type 'Microsoft.SharePoint.Administration.SPService' from assembly 'Microsoft.SharePoint, Version=14.900.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c'. Server stack trace: at Microsoft.Office.InfoPath.Server.DocumentLifetime.Document.QueryDataOnLoad(DataAdapter documentDataAdapter, DataObject documentDataObject) at Microsoft.Office.InfoPath.Server.DocumentLifetime.Document.ExecuteInitOnLoadForDataObjects() at Microsoft.Office.InfoPath.Server.DocumentLifetime.Document.LoadFromRemoteContext(Boolean firstOpened, String editingSessionId, Solution solution, Byte serializedState, Byte serializedVersionState, Dictionary`2 inputParams, OpenParameters openParameters)
After a lot of trial and errors I did some reflection on the Microsoft.Office.InfoPath.Server.DocumentLifetime.Document.QueryDataOnLoad method in Microsoft.Office.InfoPath.Server.dll. The method had a small code change between the Cumulative Update the customer was on and Service Pack 2.
The small code change, FormsService formsService = FormsService.TryGetLocal(), uses Microsoft.SharePoint.Administration.SPService. The problem occurs when this code is run from within the sandbox process. Then SPService is not available just like the error message said. QueryDataOnLoad gets called if you have an InfoPath form with data connections that loads on startup.
It is really easy to reproduce this bug. Just install SP2, create an InfoPath form with a data connection (that loads a SharePoint list at startup) and also add code-behind for the loading event. Fortunately the line of code causing the problem is removed in August 2013 Cumulative Update.