Will look into why copy is failing. Low performance mode was removed anticipating that the (significant) performance gains moving away from Flash + reworking some of the code would be sufficient to resolve any performance issues anyone would be having - it's sounding like that's not the case. I'll look into bringing that back.
In the current lab, after using the "U" and "D" keys to view the 2D structures, I click on designs to get back to the list mode. I used to be able to click on cancel while in the view,vote, sort window to bring up the list. It will no longer respond to my clicking on cancel. It sometimes makes a clicking sound when I just mouse over the button. Using Chrome Ver.69.0.3497.100.