I upgraded from 1.34 to 1.38 and got Widgets error, so I used your manual for "mediawiki version 1.31 and later', it seems everything is done fine and I get no error, but Widgets.php is not under /Widgets folder. Why this file is missing from your git? I copied Widgets.php from my older 1.34 version to this new folder, but it seems there are still problems.
