I've recently been encountering an issue whereby dragging either an image or selected text on a webpage causes Safari (10.1, on El Capitan 10.11.6) to force reload the page (not a real 'crash', I guess, but a semi-crash). The page gets a slim alert banner at the top saying “A problem occurred with this webpage so it was reloaded” and a modal alert box pops up saying “Safari Web Content quit unexpectedly. Click Report to see more detailed information and to send a report to Apple.”
I've got a two screen setup with this iMac: the iMac's own retina screen, and a 'regular' resolution screen connected via VGA-thunderbolt adaptor. Further investigation has revealed that the ‘drag crash’ only occurs if the browser window is on the Retina screen. And it only seems to happen in Safari, not Chrome.
A workaround would be to move the browser to the regular screen before dragging anything, but that doesn't really gel with my workflow.
Anyone have any ideas how I can stop this from happening? Thanks.