The best way to recover a lost map is checking Intermapper Setting/Maps located here per OS - https://static.helpsystems.com/intermapper/help/UserGuide65/Content/09-Reference/09-03-Files_and_Folders/filesfolders.html
There are several locations where maps are available to restore from.
Start with the ScheduledBackups. Servers with scheduled backup enabled https://static.helpsystems.com/intermapper/help/UserGuide65/Content/08-Server_Settings/08-03-Server_Config/MapBackup.htm will have the maps saved to this location. One problem is the name of the maps are not available and the MAP ID is the only way to identify it. You will need to go to find an older copy of the map in question from the Maps>Version of Intermapper, then take note of the MAP ID and search for that in the scheduled backup folder.
If you don’t have the scheduled backup enabled or don’t see the map you are looking for in this location then try Manual and Automatic locations.
Another option is to Check Maps > previous version of Intermapper (6.X.X) > Enable and try restoring from here.
You can use the File > Import > Map to do one map at a time. Otherwise, stop the Intermapper service and copy multiple maps at once and paste into the desired location and start the service.