I am having a very strange issue with VS 2012. When in design time of a winform application if I open a specific form the login form appears on the screen, not as in designer, but as if the application had been launched.

I can open the login form in design time
![The login form in design time](https://i.stack.imgur.com/irPVU.png)

but when I open another form called Print this happens ![enter image description here](https://i.stack.imgur.com/K09Ll.png)

Clearly the form I have tried to open has not opened in the designer, and instead the application seems to have been launched. If I interact with the form by closing it then visual studio crashes. Also in the task manager the process is Devenv.exe.

I have tried clearing the obj and bin folders with no luck.