Diagnostic Viewer hangs with big models in R2014a

Anybody else have the Diagnostic Viewer completely hang up in R2014A?

Happens mostly during model updates or builds with big models.

Showing on 2 different PCs, one on WinXP, one on Win7.

Doesn't matter if you stop the script or not - the viewer is hung, and the little blue spinning flower petals just keep spinning for ever.

After the error, the diagnostic window is stuck and cannot be used anymore until you restart the MATLAB session, or perhaps if you close and open the model again.

If the error happens during builds, the build itself still completes and the core Simulink functionality is still okay. Its just the diagnostic viewer which is hung.