I am currently moving from IE to Firefox.
However, Firefox keeps telling me that I have to login (which of course I have), whenever I try to edit one of my racks or make a new one.
I have looked everywhere in Firefox, have enabled Cookies, Javascript, and everything else that looks like it could have something to do with my problem.

With IE, everything still works just fine.

Any idea?

Sounds like a cookie issue, but sadly I am not sure. Do you have an adblocker that might interfere with the site? Did you try the "keep me logged in" option?

Cookies are allowed, no adblocker active. Tried with and without "keep me logged in".

I'm without a clue here ...

Does the problem occur with ANY of your racks? If it is a special rack can you send me the link.
Does it work in Chrome/Chromium browser?

I have yet to try each of my 31 racks, but the problem definitely occurs on all that I have checked so far (approx. 10).
Just gave Chrome a try and, funnily, it worked like a charm.

I'd like to stay with Firefox, though, for a number of reasons.

Am I the only one with this problem?

Firefox should work. I have tested it on MacOS and Win10. I haven't heard of others with this problem yet, but maybe they just did not report.

Just tried Firefox from my wife's notebook, and, surprise surprise, no problems whatsoever !!
So it's definitely Firefox on my PC that doesn't do what it ought to.
Think I'll have to de-install/re-install it completely. Oh well ....

Thanks anyway, MG!

Just in case someone else faces the same problem as me:
a de-install/re-install of Firefox did the trick. Everything's fine now, pheew!

Just don't forget to save your favourites before de-installing.