well i deleted it cause it wouldnt install when it was in my list. so its gone. now when i click "via curse client v3" it wont work. matter of fact nothing even pops up. wtf is goin on.

I've been having this problem as well. For a while the curse client will randomly tell me that my questhelper no longer matches the database and has been modified...I never touched anything in the questhelper files. That was usually solved by re-installing the addon. But the last time it happened I uninstalled it and the curse client wouldn't reinstall it. The bar would come up for retrieveing data for a split second and go away and then nothing happened. No addon. Sometimes nothing would show up. I installed the addon manually and the curse client didn't detect it.

If you get the "xxx addon no longer matches..." message, it means you are are trying to update the addon with more than one updater. I use both Minion and Curse Client, and make sure that if an addon is found in both, then only update it in one or the other.

The issue is caused by the different methods of downloading and installing that different updaters use.

rebelpride: did you try finding QuestHelper in the client itself under "find more addons" or "get more addons"?

seems like there are many of us in this same boat. what can we do to solve this ? i miss my questhelper !

download it manually, and move it to the add on's folder.. :) replace all of the old questhelper folders with the new download.. 

The other option you have is to install the v4 beta of the client. You can find it on both curseforge.com and wowace.com on their front pages. I know QuestHelper is found there, I just saw it a few minutes ago.

Two things of note: first, the v3 client is no longer in active development, and I *may* be wrong but I don't even think bug fixes are coming. The second thing is the v4 client is in BETA for Windows, so expect frequent updates to the software, and some features might be missing or disabled. That said, it is already leaps better than v3 ever was.