Unhandled Exception: System.Web.Services.Protocols.SoapException: Server was unable to process request.
Not have enough privilege to complete Create operation for an Sdk entity.
It looked pretty strange because your user might be having System Administrator role and in CRM it might be having all the rights.
Note: The Active Directory account used to deploy and register new assembly into CRM 4.0 database has to be added into Deployment Administrators group in CRM Deployment Manager.
Here are the steps to accomplish this:
1. Open CRM 4.0 Deployment Manager Console (Start -> All Programs -> Microsoft Dynamics CRM -> Deployment Manager).
2. Go to “Deployment Administrators” node and choose “New Deployment Administrator…” option.
3. Insert appropriate user and confirm selection by clicking “OK” button.
After completing this step, your users will be able to register and deploy the assembly successfully. So, remember about this when you try to deploy plug-ins with user that you added to CRM.
Happy Coding :-)