This add-on might help you

https://addons.mozilla.org/en-US/firefox/addon/delicious-bookmarks/

Thank you.

That would be a question for Delicious support or Help.

Have you tried some basic Firefox troubleshooting, like the Firefox SafeMode?
https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-using-safe-mode

Firefox 25 was released 6 1/2 weeks ago and this is the first mention I have seen in this forum about Delicious keywords no longer working in Firefox 25 and above.

@SukanyaMandal: That was the add-on I'm talking about.

@the-edmeister: I always thought, that extensions won't be available in SafeMode. I can try of course, if the problem remains when disabling all other extensions.

I think you should try it in SafeMode. Delicious tags aren't compatible with Firefox built in tags, but I would expect the keywords to be inside Firefox and not dependent upon that Delicious extension being enabled.

Tested, if keywords work without delicious even in FF 24. They don't :(

I'm having this issue too. It's pretty frustrating. Have you made any progress?

@adambrock: I'm glad to finally find out, that I'm not the only one - no progress yet, still using FF 24.

I'm currently thinking about switching to some other bookmark sync system and got the impression that there should be ways to import Delicious bookmarks into FF again.

Found a Python script on https://bugzilla.mozilla.org/show_bug.cgi?id=416611 by Gumbeto that allowed me to import the file I exported from Delicious with tags. I uninstalled Delicious plugin about an hour ago und updated to FF 26. Nice side effect: FF is faster now :)