I'm not sure that is correct.
No, it isn't correct. The dialogue shown in your image Tuneup is a Folder Selection Dialogue. A folder will only show a Plus sign if there are more folders beneath it that can be selected, and it correctly does not identify ZIP files as folders like Windows Explorer does.
While my Windows 10 looks a little different to your Windows 7, in that Win10 uses Disclosure Triangles while Win7 uses the Plus sign to indicate more folders, you can see in my attached image that my "Library Backups" folder doesn't indicate there is more to see inside it using the MC Folder Selection Dialogue, and yet the Windows Explorer window shows that it is full of ZIP files. Also note that Windows Explorer does recognise ZIP files as folders, shows the Disclosure Triangle, and shows the ZIP files in the folder tree on the left. My image demonstrates that a Folder Selection Dialogue works differently to Windows Explorer.
Tuneup, I hope you didn't scroll around selecting folders in there, and then click OK, because if you did you just made it much harder to help you, as you would have changed the location of your Library Backups.
Anyway, I always find the best way to locate Library Backups is to just go to the top menu in Standard View and select;
File > Library > Restore Library
Your Library Backup location will be shown in the dialogue window that opens, and if you click Browse you will be shown a list of all recent backups, in ZIP files. Make sure that files listing is sorted by "Date Modified", preferably in reverse sort order. i.e. That the most recent file is at the top. That will work as long as you didn't change the backup location earlier.
Select a backup from before the problem started and restore it. Yes, with settings as well. Why not. MC will want to restart to apply the settings.
If you did unintentionally change the MC Library Backups location earlier, go back into the "Tools > Options > Files Location > Program Files > Library Backups" dialogue and set it to;
C:\Users\7-Pro\Documents\JRiver\Media Center 25\Library Backups
again and then use the Restore function.