On Mac, sometime, the page loaded is not rendered and the checkboard of tiling is the only thing visible. It can happen randomly (but not frequently) on any webpage.
This issue is not due to a missing region update, forcing an update does not show the page, the checkboard is just repainted. Resizing the window show the content.
Same thing on Linux.
*** Bug 39069 has been marked as a duplicate of this bug. ***
Is this still an issue?
This was fixed in http://trac.webkit.org/changeset/59760
*** This bug has been marked as a duplicate of bug 39294 ***
...or https://bugs.webkit.org/show_bug.cgi?id=39218. At least I haven't seen this with the current trunk.