Error after restoration with NT Backup

[BBRAAM]

I had to restore a site (on the same server) and have used NT Backup. I have read their documentation and the restoration went well. However, after restoration the frontpage shows a 404 error and all menu links were inactive, but after a while the menus became active and the subpages can be viewed. But the frontpage still shows a 404 error. 

The reason for the backup has nothing to do with the frontpage, and in the backend everything seems ok with the menu and frontpage, so I do not understand why I get a 404 error. I did not get an error message during the restoration, but a message that restoration was a success.

I have tried to ask the NT Backup support, but they do not answer, so does anyone of you have an idea why I get a 404 error, and how I solve it?