Sometimes software surprises me. Somehow it just inexplicably stops working the way we expect it to. What is even more surprising is how somewhere, someone has a solution to this problem you are facing.
I am using Visual Studio Ultimate 2012, and the other day while writing some code for a blog post, Intellisense suddenly stopped working. This happened while I was coding and wasn’t a result of me installing anything or removing anything. It literally worked the one minute, and stopped working the next.
Perturbed by this situation, I set out on a (very short) quest to find out how to fix this.
Intellisense stopped working Visual Studio 2012 – Solved
As you can see below, the dot after my XmlNode type towns didn’t pop up the intellisense menu. The solution (although a strange one) is quite an easy one to resolve.
Right-Click the menu that pops up when hovering your mouse over the left bottom corner of the screen in Windows 8. From the start pop-up click on Run. In the Run command, type %AppData% and hit enter.
This will open the Roaming sub-folder in the AppData folder.
Open the ‘Microsoft’ folder
In the ‘Microsoft’ folder, select the Visual Studio sub-folder.
Here you will see two folders. One called ‘10.0’ which is the Visual Studio 2010 folder and one called ‘11.0’ which is the Visual Studio 2012 folder.
Next you have to rename your ‘10.0’ folder. I just renamed ‘10.0’ to ‘10.0_OLD’. Be aware though that if you have Visual Studio 2010 installed, you will lose all your Visual Studio 2010 settings and preferences (This doesn’t affect your projects though). Continue renaming all other folders, leaving the ‘11.0’ folder for Visual Studio 2012 as is.
Restarting Visual Studio 2012, the Intellisense is back and functioning as needed. It seems as though when I uninstalled Visual Studio 2010, the ‘10.0’ folder wasn’t removed during the uninstall process.
While this isn’t a critical bug as some would like to believe, it is a bit frustrating. Luckily it is easily solved and not the end of the world as we know it. Initially I tried Tools -> Options -> Text Editor -> C# (or All Languages) -> General and checked if ‘Auto List Members’ and ‘Parameter Information’ was enabled (which it was). Restarting Visual Studio also didn’t help. I hope that the above will be of use to someone.
UPDATE (11 May 2015)
I recently experienced the same issue on Visual Studio 2013. This caused Intellisense to stop working, but this was just after I had installed CodeRush. See the article CodeRush Stops Intellisense Working For Visual Studio 2013 for more.
Reference: Haney Codes .NET