I had a situation similar to this. Even though the SQL Server Configuration Manager showed that Force Encryption was "No" and the certificate page was clear, I continued to get this error and was unable to start the service at all.
In the registry (for my installation):
HKLM\SOFTWARE\Microsoft\Microsoft SQL Server\MSSQL10.MSSQLSERVER\MSSQLServer\SuperSocketNetLib
The Certificate String had the value equal to the hash in the error message. Removing that value worked for me.