Dave - I haven't seen the "An error has occurred in the Script on this page" again since cycling the Hide script error check box a few times and restating DXKeeper and Pathfinder. But is reference to the issue of:
Seeing the error of --- a small window popping up saying === A call sign not found even though the lookup info is entered in the Capture window and shows in the Pathfinder window"
and you asked
+ What's an example of a callsign that produces the above behavior?
a couple that this happened on are JH1RGG, K5DX, K5LG, NA5DX, K5PXP
73 & tnx