Are you sick and tired of getting that annoying debugger break in Visual Studio caused by the addeventlistener Null Object Reference exception!? Well, after tons of googling I still couldn’t find the resolution. What I noticed is that after doing Windows Updates sometimes after the PC restarts the error would stop (for a short time). For me the error was occurring on Internet Explorer 9 but it’s possible that you may experience the same symptoms on prior version of the IE.
1. Open Internet Explorer 9
2. Click the Tools menu (if you don’t see it, don’t worry, just hit the ALT key on your keyboard and it will appear) then click Manage add-ons
3. In the list of addons on the right pane, click on any add-on then press CTRL+A (this will select all your add-ons… also you may want to take a screenshot or write down which add-ons you have enabled so that you won’t forget which ones you had enabled)
4. Next, click the Disable All button at the bottom right hand side of the screen
5. Click the Close button
6. Open Visual Studio .NET and load up the website that you know causes the addeventlistener error and vuala, no more error!
At this point what I did is enable each add-on one by one and test my project to try to figure out which one was causing the exception (in my case the add-on was called “Discuss”).
I hope this article was helpful, happy programming! J