(Note: I found no better category for a feedback/question on the owncloud dot org webpage itself. I hope that this is ok.)
I could not find a way to report on two broken links on owncloud dot org. Can you point me to the right place? Thanks!
Here are the details, if any webadmin sees this post by chance:
The links on page  https://owncloud.org/download/older-versions/ to the Linux packages for Owncloud Server 8.2.x and 9.0.x lead (with a redirect) to non-functional pages:
 as , but with 9.0 in the url (No link, as I can only post 2 links as new user)
For the older versions (8.1.x and earlier), the links to Opensuse are working. For the newer versions (9.1.x and later), the links redirect correctly to pages very similar to  and , but with a trailing slash. If you add a trailing slash by hand to the URLs, also the pages for 8.2 and 9.0 work.
Please add a trailing slash to the links on  leading to  and  to make them work / redirect correctly.
Without finding these pages, people cannot follow the iterative upgrade from older versions, see Admin Manual --> Maintenance --> Upgrading --> Upgrading from Package --> Upgrading Across Skipped Releases (sorry, no link, as I can only post 2 links as new user).
Additional, related problems further down the road: For 8.2.x on Ubuntu 14.04, the respective packages referenced on https://attic.owncloud.org/download/repositories/8.2/owncloud/ seem not to be available any more. (For 8.1.x on the Opensuse server, the packages for Ubuntu 14.04 were still available, although the release key was expired .) – I know, Ubuntu 14.04 is outdated, but that’s why I try to migrate away from it step by step …
First of all: You are absolutely right. I don’t have a serious problem here. If the upgrading fails, I will do the clean setup as you suggested. Also, I’m not under time pressure. It is rather the challenge to upgrade my old setup to a current one while keeping my data and configuration. Everything is relaxed. I don’t try to get help here.
To summarize what I already reported in previous posts, to make my intention more clear:
(original post) the missing slashes at the end of the links  and  on page . Here, I just suggest repairing the links by simply adding these slashes.
(last post) the package for 8.2.x on Ubuntu 14.04 referenced here  that is no longer available. Here, I suggest
to either remove the references from  (and from the sites of other versions offering removed packages) (my preferred suggetion, but that would require housekeeping after each package removal.)
or to amend a general statement to the sites  and  for the sake of completeness, e.g.: “Note: Packages for outdated operating system distributions might be no longer available, despite still being referenced. In that case, please resort to a manual upgrade.” (This has the advantage that it excuses all broken links/references for outdated and removed packages.)
I will also update the title of this thread to make that more clear.
Meanwhile, I discovered an additional problem with the update. However, that is rather package related and not documentation related, and I will describe it in a separate post. (Package for oc 8.2.x on Ubuntu 16.04: Keys expired and wrong dependencies).
For the problems with the repositories/packages, I will definitely submit them at core/issues, not here in the forum.
For the problems related to the actual documentation , docs/issues is surely a good place; however, could you please confirm that this is also true for improvements for the download pages [1,2,3,5]? They are not strictly “documentation”, but rather parts of the website.