Guide
How to install After Effects extensions safely (CEP, ZXP and manual)
Jun 2026 · 6 min read
An After Effects extension is a CEP panel: HTML and JavaScript in a folder, plus an ExtendScript host that talks to the app. Installing one means putting that folder in the right place and restarting After Effects.
On Windows the shared location is %APPDATA%\Adobe\CEP\extensions; on macOS it is ~/Library/Application Support/Adobe/CEP/extensions. Anything installed there appears under Window > Extensions once After Effects restarts.
Blank panels are almost always one of three things: an unsigned extension without debug mode enabled, a stale CEP cache from a previous version, or a runtime mismatch — older After Effects builds ship an old Chromium that cannot parse modern CSS and JavaScript.
That is why fresh-install matters. Clearing the CEP cache before copying new files prevents a half-old, half-new panel, which is the most confusing failure state there is.
Verify before you trust. A published SHA-256 checksum lets you confirm the archive you downloaded is the archive that was built. And keep a rollback path: a script that restores the previous version turns a bad update from a lost evening into a thirty-second fix.
Ghostae ships with a silent install flag for multi-machine setups, checksum files for every archive, and a rollback command — because updates land mid-deadline whether you planned for it or not.