Greetings,
I have been taking looks at https://fsfe.org/campaigns/pdfreaders/buglist.en.html, and I have discovered that quite a few URLs once reported as bugs do not resolve (404) any more, or do not contain any proprietary PDF reader advertisements. This seemed to be especially common for German institutions. If someone has time, please, take a look at the bug list, and either find a new URL containing a bug for such institutions, or being unable to do so, close the bug.
Faithfully,