Can't stop Visual Studio 2015 lagging for seconds in JS files saying "JavaScript language service is processing your request in the background..."?
I stopped the lagging by editing _references.js and setting autosync enabled="false" and removing a ton of 3rd-party (angular, ionic) library files from the listed references.
<autosync enabled="false" />to the top of _references.js file
If previous answer is not clear enough or tl;dr
add
/// <autosync enabled="false" />to the top of _references.js file
I faced the same problem. I have installed the latest updates but the problem remained. Then, I disabled the 3rd party add-ons one by one. It now works without any problems. It is clear that some 3rd party add-ons have bugs causes visual studio malfunctioning.
Hope it works.