PopupTemplate fails on the sketchWidget graphicsLayer at 4.21 here is a code sample (draw a rectangle with the rectangle tool to show popup)
Am I doing something wrong ? Anyone had the same problem ?
Sorry, I've tried to get a workaround but this should be working. In the error is the message "Instance of 'esri.layers.GraphicsLayer' is already destroyed", but I can't figure out why that would be happening. I'm thinking you should open a ticket with Esri on this one as it looks like a bug to me.