I'm sorry, I was still working on the "The path is not of a legal form" problem.
Since you have a stack trace, navigate to the point of failure:
In the CabanaLib solution, expand the IdeaBlade\IdeaBlade.Cab.DevEx project and edit \Views\Base\DevExDetailGridViewBuilder.cs.
The exception occurs at line 71 (in CreateDetailGrid():
mDetailGridView = gbm.AddRelationView(displayName, descriptor);
and indicates that we are trying to assign to a variable of type GridView from an array of GridViews.
Confirm that the member mDetailGridView is declared as a DevExpress.XtraGrid.Views.Grid.GridView at the bottom of the file.
This is being assigned from the result of gbm.AddRelationView(). gbm is declared two lines above as an XtraGridBindingManager. Mouse over this class name and be sure that Intellisense says it is
Right clickon AddRelationView, select GoToDefinition and choose the first definition in the Find Symbol Results window. The result is a DevForce assembly so you can only see the metadata. Mouse over the resulting tab to see the assembly source file. In my copy it is
IdeaBlade.UI.Winforms.DevExpressControls.v7_2_1.dll version 2.0.50727.
Is yours different?
Let me know the results and we'll go from here.