We have had reports that newly implemented NLD Auto Updater makes some Anti Virus programs go bongus!
Some blocks the download of the updated files and others simply refuses to run NLD.
You can still run NLD without any problems and worst case you can just download download NLD again manually like before the auto updater was implemented.
We will look into it and fix it today, sorry for the false alarm!
If you have any experiences with the NLD auto updater clashing with AV, please comment on this post.