Maybe we can refactor this cancel confirm route so it asks your password one last time.
Something like changing the link form cancellation_url to /user/login?destination=cancellation_url, which should transparently
- if not connected, makes the user land on user login form instead of unattended 403 (making it understand it may login in order to confirm the cancellation of its account)
- if connected, makes the user land to the cancellation confirmation page
?
Added a back link to the module project page directly from description (usefull when accessing this doc page from a search engine result) so that it's not necessary to scroll to bottom to find this link as related content.
Just a modification to make the problem explicit in the title so that others metting this problem may identify it better.
I am also facing the issue on a taxonomy term page.
Before searching in core issue queue, I realized my MariaDB configuration was the default one and I upgraded it according to https://www.drupal.org/node/259580 → with a single effect: the "MySQL Server has gone away error" has been replaced by a PHP out of memory error (512 Mo allowed).
Patch from #15 has fixed the situation (thanks Defcon0).