I had edited 500 color photos in a quick collection. I copied them to their own collection. I then created a new collection from that collection and called it B&W. I then converted the new B&W collection to black and white. When I went back to my color collection they had all turned to black and white. Hmmm...so I reverted the the color collection and watched as all my edits reverted back to the unedited images...in both the B&W and color collections. So all I have now are two collections with unedited images. I'm not real savy on all this so I will need my hand held if this can be fixed. Are my edited images lurking somewhere? During all this I never closed LRC.
It is going to depend on how you did the original edits. If it was one at a time, you can go through each one in the Develop module and use the "History" panel on the left, If you did the Quick Develop in the Library Module, you may be able to use the selections and multiple taps of CTRL+Z to back up. No matter what you try, the original image files will remain "safe" unless you delete them.