I just installed Flash Builder 4 and selected a small project I was working with in Flex 3. It gave me a warning upgrading the directory which I did and loaded up the base .mxml file. I ran it and it worked ok. I then went into design mode to add more controls and the window is blank. I tried to refresh and still nothing. Any ideas on how to get around this?
Edit: More info
I created a new flex project and I get the design window. Also in the original project I can add items, say a button, to the design window but it dissapears when I release the mouse button. However, it does add it to the code and I also see it when I run the project.
Edit: Even more info
In the new project I created I copied over the source XMLListCollection and added it into the Declarations tags and the visual controls but left the application header intact. I lost the ability to see the design view after I did that. So I commented out all the code I put in place and still got the same issue with dragging a control onto the page and it dissapears. However, it shows in code and also shows when running. Again, everything else is commented out. I then deleted all the code except for the original code put in place by Flash Builder 4 and encounted the same issues.