DesignInstance not working in VS2012

Question

I just spent several hours on an issue when using VS2012, WPF 4.5 and design-time data, specifically the DesignInstance attribute.

Goal: I wanted to

Answer 1

I ran into this error myself in VS2013 then found this question. After searching more, I found an answer that helped me solve it.

instead of

d:DataContext="{d:DesignInstance vm:DesignAlertsViewModel, IsDesignTimeCreatable=True}"

use

d:DataContext="{d:DesignInstance d:Type=vm:DesignAlertsViewModel, IsDesignTimeCreatable=True}"

I was using "...d:DesignInstance Type=vm:..." and that displays the same error described above. As soon as I add "d:" everything works.

Here is the thread I found that helped.

https://stackoverflow.com/a/21690404/2892400