Why the version error appears
AE checks project version metadata before loading the full file. If the signature is newer than the app supports, opening can stop immediately.
Official save-down vs browser conversion
If newer AE is available, official save-down is ideal. If it is not available, a local browser converter can create a compatible copy for testing.
What to inspect after opening
Review effects, expressions, missing plugins, fonts and footage paths. Solving the version error does not guarantee visual output is identical.