Varna popup causes crash on some Macs

[njbooher]

Workaround for now is to turn off global refold

might be big-sur specific

[rjandr]

When the ScanFold gui window is "docked" with igv I see non-stop tab switching which eventually results in unresponsiveness, requiring force-quit:

NotPoppedOutDontWork.mov

The error sometimes goes away when the gui is undocked:

PoppedOutWorks.mov