I am building a new campaign and several maps I am using have just disappear!

I am building a new campaign and when I opened my game this evening, I noticed that several of the maps I have set up and populated with tokens have disappeared.  Also, the map I used on the Campaign Page was missing as well. Is anyone else experiencing this?  It is very frustrating - everything was fine yesterday when I last worked on the campaign.  More than several hours of work and I am fearful of this continuing.  Any suggestions / resolutions that people have would be greatly welcomed.

When you say "maps have disappeared", do you mean the images on the maps have disappeared, or do you mean the pages where you constructed the maps have disappeared? If you remove the images from your library, it will break all the images on the pages.

Thanks, I will check to see if I deleted any of the images from the library, but I don't recall having done so.