When enabling extensions in the ACP, one will sometimes receive the error:
The selected extension is not available for this board, please verify your phpBB and PHP versions are allowed (see the details page).
It would be helpful to know what, specifically, triggered it.
Likewise, this does not happen when the extension is enabled via command line:
./phpbbcli.php extension:enable whatever
So those checks are skipped, and presumably shouldn't be,