My SketchFlow Player is empty:

image

Let me officially call this the Grey Screen of Death. You create a lovely sketch flow prototype in Expression Blend and it looks great at design time, but at run-time you get nothing. If you’re clever, you’ll try to dig into the java script error, which fortunately, the nice folks on the SketchFlow player team have raised up from the Silverlight layer. Unfortunately, I’ve found that most errors you get in here are pretty useless.

In my case I was recently getting:

Webpage error details

User Agent: Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; WOW64; Trident/4.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; InfoPath.2; MS-RTC LM 8; .NET4.0C; .NET4.0E)
Timestamp: Wed, 31 Mar 2010 03:58:03 UTC

Message: Unhandled Error in Silverlight Application AG_E_PARSER_BAD_TYPE [Line: 5 Position: 78]   at System.Windows.Application.LoadComponent(Object component, Uri resourceLocator)
   at SilverlightPrototype_10Screens.Screen_1.InitializeComponent()
   at SilverlightPrototype_10Screens.Screen_1..ctor()
Line: 1
Char: 1
Code: 0

Your mileage might vary by attaching the visual studio debugger or running the application from within Visual Studio. In my case, I ended up doing some process of elimination pruning to see if I could back track and find the problem. I was having difficulty with some sample data in this case. It was tricky to find, but I’ve determined that you really don’t want a space in your SketchFlow project names. This will cause some erroneous code gen for the loading of the sample data in the sample data classes.

I absolutely love Expression Blend and SketchFlow, but finding this bug was one of those times when I’ve wanted to physically hurt my computer. I hope this helps some poor soul find the root cause a little faster than it took me.

And please share in the comments any other common reasons you’ve found SketchFlow Player failures.