As was already mentioned you will need to restart the Event Broker in SQL. You can use the SQL in the post referenced below or you can use the SQL Management Studio GUI as well (FIMService database properties, options, Service Broker, Broker Enabled).
Note that if you roll back your databases, you do roll back all of your data. Any data changes that were made since your last backup will be lost. For data that is just being synchronized through FIM you probably won't have issues, but if you have any data
that is sourced by FIM, it will be lost. Examples of data sourced by FIM would by any edits to users or other objects in the FIM Portal / Service, self service password reset registrations, workflow approvals, etc. If you have email notifications that trigger
off of data events (such as provisioning), you might end of sending those notifications again. If any of your workflows reach out and touch things (via PowerShell or custom activities), those external events won't be rolled back and may occur again. In the
Sync engine you would lose any manual joins or disconnections - these would be rare, but if they are part of your normal process, you don't want to overlook them.