I try to View/Edit Excel documents (xlsx) in Office Web App SP1. I immediately get an error. "An unexpected error has occurred.". Word and Powerpoint both work fine. I have recreated the Excel Service Application with success, but it shows the same exact error and ULS logs the next day...
This is in my ULS Logs:
Process: w3wp.exe
Level: Unexpected
System.Security.SecurityException: That assembly does not allow partially trusted callers. at System.Security.CodeAccessSecurityEngine.ThrowSecurityException(Assembly asm, PermissionSet granted, PermissionSet refused, RuntimeMethodHandle rmh, SecurityAction action, Object demand, IPermission permThatFailed) at System.RuntimeTypeHandle.CreateInstance(RuntimeType type, Boolean publicOnly, Boolean noCheck, Boolean& canBeCached, RuntimeMethodHandle& ctor, Boolean& bNeedSecurityCheck) at System.RuntimeType.CreateInstanceSlow(Boolean publicOnly, Boolean fillCache) at System.RuntimeType.CreateInstanceImpl(Boolean publicOnly, Boolean skipVisibilityChecks, Boolean fillCache) at System.Activator.CreateInstance(Type type, Boolean nonPublic) at System.RuntimeType.CreateInstanceImpl(BindingFlags bindingAttr, Binder binder, Object[] args, CultureInfo culture, Object[] activationAttributes) at Microsoft.Office.Excel.Server.MossHost.MossHost.TryCreateHostExtension(String className, IHostExtension& extension) at Microsoft.Office.Excel.Server.MossHost.MossHost.LoadHostExtensions()
Just a couple notes:
Excel Services is running.
Office Web Apps feature is enabled on the site collection.
Word and Powerpoint work fine.