I was making an animation and then descided to mirror one of the objects because I had forgotten to do that earlier, I also moved it a bit before, but I forgot to turn off the record button for adding or changing keyframes. I selected the keyframe on the timeline and clicked delete keyframe and chose ‘Available.’ Then Blender crashed. Unfortunately I had saved before I did this and the reason I didn’t undo it in the first place was because I had done some other editing before I saw the keyframes. The object I had mirrored after moving had a blue line instead of a yellow line to identify the keyframe on the timeline. I’m not sure what that means, but it might be the problem.
A blue line indicates a keyframe in the "pose mode " - usually for armatures.
you can check your backup blend data in your c: mp directory