Universal Analytics = 50% drop in traffic that I cant confirm

Hello,
I am having trouble with Google Analytics.
After I updated to the universal tracking code my traffic dropped by about 50%. However, when I look at Webmaster Tools I don't see a drop in traffic – all clicks are the same as before I updated to the universal code. Also, when I look at the pageviews from Adsense there is nothing to indicate a sudden drop in traffic.
I tried lowering the Session Time from 30 minutes to 15, but that didn't seem to help.
Any…
Universal Analytics = 50% drop in traffic that I cant confirm

See original post by Dani__