It's been a while since I gave up on this, so I forgot all the names.
I remember a quest where you had to help an Arogian to deal with the Skooma problem. After I went to the warehouse and took out the ''dealer'' and came back to the Jarl, I had to go to a cave. Went there, killed everyone and it even said that the objective was completed. But I didn't receive an objective afterwards.
Is this a bug or do I miss something?

Anyone?

Maybe the quest had finished then?

Would have thought you could have gone back to the guy for a reward though.

give us a few more details....

quest name?
platform you play on?
have you tried a prior save?
what does your quest log actually say about it?

@lozzykinz: I tried coming back to the Jarl. No result.
@geckoman: I'm on x360. It's been a while ago so no, I don't have the save. The quest is in my quest log, but it says that the objective is completed. Normally, I would be supposed to come back to the Jarl now. I found out I'm not the only one:
http://www.thenexusforums.com/index.php?/topic/488236-problem-quest-skooma-riften/
http://www.gamespot.com/the-elder-scrolls-v-skyrim/forum/cant-complete-jarls-quest-in-riften-spoilers-61259945

ya seems that one can cause some problems. i zoomed right through with no issues so who knows. in any case without a prior save you might just be stuck. i'd just go on about your business and every now and then check back and see if it will complete.

Thanks I guess. I hope they patch up this one soon.