I have 23 quests in my quest log and I am not able to pick up another quest. I have counted them several times and 23 is the total. It doesn’t track the quests count anymore, so counting was a pain, but I counted several times and I should not be at the 25 limit. Why is there a limit anyway?
The game uses your quest limit for a couple of other quest related systems like the daily emissaries and the war campaign. There isn’t a way to prevent it.
The limit is because people are silly and just keep taking more and more quests without doing them. If the limit was 1000 there’d be someone who picks up 1000 quests and doesn’t do any of them. Just do the quests you picked up. It isn’t unlimited because they have to retain the status of any active quests in the database. It’s the same reason we don’t have unlimited bag space.