Top issues:
- Powershell prompt not started with run as administrator (UAC)
- You are not a local admin at all,
- You don’t have access to database in SQL. Snapin must connect to SQL database.
For the UAC stuff, you can use Process Explorer to be sure you are really an admin (UAC elevated):
- Deny : You are memver but UAC is blocking you (filtered). Restart with run as administrator
- Owner: You are really admin with UAC elevated. Check SQL rights 😉