How to make a newer AE project open in an older version
The usual cross-version handoff problem in After Effects is simple: the project was saved in a newer release. If the recipient cannot upgrade, the .aep has to come down to a version it understands.
AE targets must be older than the source
The target has to be strictly older than the project. If the source is AE 2023, you cannot downgrade to AE 2023; you pick 2022 or an earlier available target.
Choose the closest workable target
Expressions, effects, layer properties and project structure all change over time. Older targets require more cleanup, and complex projects may need manual inspection.
Local browser conversion helps with sensitive work
The After Effects line runs in your browser, so the file is not uploaded to a server. That matters for client projects, unreleased packaging, internal templates and confidential work.
Check fonts, media and expressions afterwards
The downgraded project still references the original fonts and media. Open it and inspect comp structure, footage links and expression errors before delivery.