I use the latest version of Opera (41.0.2353.46) on a Surface Pro 3 running Windows 10 with all the latest updates.
When using Opera to read PDF files from the internet, Opera crashes when I try to snap it to either the left or right side of the screen. I'm trying to read a PDF from a site while at the same time taking notes in OneNote. This only happens when tablet mode is enabled in Windows 10. When I snap, instead of Opera snapping to the side, Opera dispapears. The first couple of times Opera doesn't seem to crash, just gets hidden. But if I try three or four times, Opera ends up crashing.