my project doesn't display video previews

my project doesn't display video previews of the same version. i edited my project then decided to rearrange the order of the clips, everything worked fine up until the export, and now in the playback the rearranged clips appear black but the original (in the same timeline) plays back perfectly fine. i've tried restarting my pc and the project multiple times, as well as pre renderering the footage and nothing is helping.