You can recover from this situation if you have some backup snapshots, usually located in the snapshots folder
Stop Redpeaks service, and wait that its process is terminated
Move, rename or delete the uiweb folder, containing the DB files.
Restart Redpeaks server: A new empty database will be created
Log in using the admin user credentials configured during the installation.
Go in the snapshots menu and apply the latest snapshot
The server will have recovered its configuration.
Have a look in the Admin→System section and check data retention settings.
It is advised not to keep monitor jobs results more than a couple of days.