Lately I've been working on some visual studio add-ins and plug-ins. I'm testing a few new ones and even playing around learning how to develop one of my own. Doing so did cause me to break the IDE leaving me in all sorts of weird situations. For example one time I messed it so bad I couldn't even create a new .NET project any more. For some reason the IDE insisted that I'll install some language tools (or something alike).
In the past this got me into a reinstall process which in most cases does solve the problem however does take about an hour or so.
Lately, I found that in most cases, issuing a reset command does in most cases solve the problem as well. So when having problems with VS-IDE before reinstalling try the following:
Reset the Visual Studio IDE
using the command: devenv / resetsettings.
note: it might be worth backing up the current setting to avoid the need to set everything again after a reset.
Reset a specific Add-in
using the command: devenv /resetAddin AddinName.Connect
note: this should reset the Add-In to its original state, which should make it work again.
More command line switches can be found here