Hi Ady,
So far we have not been able to find the exact cause behind this error, but according the stack trace the exceptions seem to be related to a problem when creating a "Measure.Options" region. According to the exception message, it seems that the ContentControl where this region is being attached has its Content property populated or bound to a source (for example, by using aBinding):
"An exception occurred while creating a region with name 'Measure.Options'. The exception was:
System.InvalidOperationException: ContentControl's Content property is not empty.
This control is being associated with a region, but the control is already bound to something else. If you did not explicitly set the control's Content property, this exception may be caused by a change in the value of the inherited RegionManager attached
property."
In would be helpful if you could provide us with more information regarding this region, for example, where the region is declared, how it relates to other regions, etc. so that we can help you find the cause behind the exception.
Regards,
Damian Cherubini
http://blogs.southworks.net/dcherubini