osCommerce 2.3.1, when we try to activate to plugin by clicking on the green circle in catalog/admin/star_product.php?action=off, it gives me this warning and the page stop loading (the action itself works, but the page will not load until we remove ?action=off in URL) :

Warning: Cannot modify header information - headers already sent by...

This .zip contain all the files of the last upload with the fix.

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