What I have done so far is an upgrade from MW 1.25 to 1.31 to 1.32 to 1.33 to 1.34 to 1.35, which, as a result, is creating a wiki with defects.
For the migration to MW 1.31 and 1.32 I just ran update.php
For the migration to MW 1.33, 1.34, and 1.35 I ran update.php, (the script is counting migration errors all over the place), followed by cleanupUsersWithNoId.php (force), with the latter again doing nothing.
The upgrade from MW 1.32 to 1.33 appears to be causing the wiki to derail, as noted in Topic:Vy4x2pb18ebrvqix. Additionally, and quite unfortunately, about 10% of the files were "disconnected" from their file pages, meaning they no longer show anywhere.
I'd appreciate some advice on how to upgrade a wiki without issues. If there is some script to be run in between, I will happily do so in the correct order, etc.