Blue Integrator provides numerous means of debugging errant Workflows.

(1) New Instance Debugging.  You can simply use the Debug | Start menu item in Visual Studio for Applications to kick off a new Workflow Instance and attach the debugger to it.  Note that this won’t use the latest VSTA code but the saved version of the Workflow itself.  You’ll be prompted to specify file locations for all incoming and outgoing Messages.  This is normally the best way of testing your Workflow prior to deployment.  When running in this mode you can use both VS.Net trace functionality, and even good old System.Windows.Forms.MessageBox. You cannot of course use MessageBox in a live Workflow Instance.

(2) Isolation.  Always try and get the cleanest possible scenario for debugging.  Stop all non-essential Workflow Instances and processes to minimize the noise whilst you are trying to rack down your problem.

(3) Tracking.  You can get a lot of information by enabling the various Tracking options on the Workflow Binding, and then using Blue Integrator Tracking to view this information.  Note that to track Messages and Variables, the relevant Tracking option needs to be selected both on the Binding and on the Message / Variable itself (as shown below).