Be careful with expressions that reference the "thisComp" name; they may break once moved to a new composition. Final Verdict
The only legitimate way to download this plugin is via the official website (AEScripts.com). Searching for "Free Download" on warez or torrent sites will likely result in malware, viruses, or stolen credentials. Un Precompose After Effects Plugin Free Download
Manually adjust the "In" and "Out" points to match the previous pre-comp container. Re-link any expressions that broke during the move. Be careful with expressions that reference the "thisComp"
There are specific scripts explicitly named "Un-PreCompose" (developed by various scripters over the years). Un Precompose After Effects Plugin Free Download