The following error message is likely the least thought out requirement of MSCRM 4.0 and a common cause of frustration for developers in enterprise customers who are using the multi-tenancy features.
Not have enough privilege to complete Create operation for an Sdk entity.
You get this error during an attempt to register a workflow activity or plug-in into MSCRM 4.0, and you may think that to do this customisation you need atleast the System Customizer role. Well you are wrong, you need higher than that. In fact the highest role for an organisation (System Administrator) isn't even enough. You need to be Deployment Administrator. This role is assigned on a server level, in the Deployment Manager tool and gives that user full powers on all organisations!
The reason I think this is badly thought out, is three fold. Firstly, I do not want to enable developers to see certain things in MSCRM in live enviroments (thus the great System Customizer role) but I want them to do the customisations. The second is if I have a developer working in a certain division or group company with it's own MSCRM organisation, I really don't want to let that developer loose on other organisations on the server (security and stability reasons). Lastly I don't want to have to give access to the server to more people than absolutely needed, and as I now need to be able to set people up to be Deployment Administrators from time to time it means extending that group of people. Anyway heres hoping MSCRM 5.0 will fix it ;)