I noticed that you are using VS2010. In my case I had to upgrade to SP1 before my Add-Ins would stop. If you Google "visual studio 2010 not stopping at breakpoints" there are other things that people have done because of this problem.
Microsoft has the update.
VB 2010 SP1
SW 2013 SP05
EPDM 2013 SP03
Thanks for the reply Dan. VS2010 was at SP1, but there were also updates available. I have everything updated but still same issue.
You may be in the Release configuration.
Best thing to do is to make sure you have the Configuration Manager shown (in Visual Studio I mean):
Tools -> Options
Show all Settings
Projects and Solutions -> General
Show advanced build configurations
Now under the Build menu, you should see Configuration Manager...
Make sure your active configruation is Debug and not Release
Change Framework version to 4.0
Thank you to everyone who tried to help.
The solution was probably a combination of everything I tried. I started trying with solutions mentioned here, among other places:
I was using Notepad as my startup application for debugging. When I set this in the Visual Studio Project properties on the debug tab, I j ust browsed and selected the notepad.exe file in the windows\system32 directory. I finally moved notepad.exe into my project debug directory (also changed the startup file path to point to this new location) and I was able to use breakpoints and debug my add in.
So while I am not sure what fixed it, the last thing I tried was copying notepad.exe out of the Windows directory. It probably had something to do with notepad being in the Windows directory.