This worked for me.
- Export the rules out to local file.
- Delete all the rules.
- Restart outlook.
- Open Rules again, if you see (client-only) rules again delete them all.
- Create any simple rule and save it.
- Restart Outlook
- Open Rules, this time you will be asked to choose which rules you want to use "client" or "server" choose client.
- Import the saved rules from step 1.
Hope this helps.