Validation issues - Source-Target Configuration File

There seems to be some weird validation going on when you click in and out of the Source-Target Configuration File textbox when it loses focus. 

Repro steps:
a.	Click in the Source-Target Configuration File box while it is empty, don’t type anything
b.	Click the Fields tab above to cause the box to lose focus
c.	You will get the message box below, seems unnecessary "does not exist"


 
