Thanks. This is a very helpful post. Unfortunately, it did not get me anywhere. On the Call Stack I see
[pluginName]!Xrm.XrmServiceContext.AccountSet.get() Line 173333
PluginRegistration.exe!PluginRegistrationTool.DebugPluginForm.ExecutePluginButton_Click(...)
...
If I look at the details of the error I get
System.ArgumentException "The specified type 'Xrm.Account' is not a known entity type"
Stack Trade:
at Microsoft.Xrm.Sdk.Client.OrganizationServiceContext.CheckEntitySubclass(Type entityType)
at Microsoft.Xrm.Sdk.Client.OrganizationServiceContext.CreateQuery[TEntity]()
at Xrm.XrmServiceContext.get_AccountSet()
at [plugin].[plugin].Execute(IServiceProvider serviceProvider)
So for some reason Account is not being found. The same works just fine on a trial account that I opened a couple months ago but not on the new trial account.