Here’s the process:

  1. Removed Windows.Controls.* from project ClientBin
  2. Added reference to System.Net so that WebClient would be recognized
  3. Changed accessibility for OnApplyTemplate from protected to public on all custom controls
  4. Changed PropertyChangedCallback to PropertyMetadata.
  5. Removed FontSize and FontFamily Dependency Properties (where implemented).
  6. Removed reference to System.Windows.Controls.Data and readded…weirdness
  7. Changed DataGridTextBoxColumn to DataGridTextColumn
  8. Set the DefaultStyleKey on all custom controls to be typeof(CustomControlClass)

I migrated a line of business application has 4 functional views, 3 custom controls, and several datagrids in just under 2 hours.

Also, upgrading to Beta 2 eliminated a weird error that I received when trying to open my solution in Blend 2.5 March. It would give a fatal error with -2142382439820943 (can’t remember the actual number)…this was after I copied the solution from one local account’s home directory to another’s. So now I have designer access back!

Thanks MS! :-)