Created attachment 307126 [details] Test page http://jsbin.com/dagikonove/edit?js,console (also attached). On that page Safari Version 10.1 (12603.1.30.0.34) and 10.1 (10603.1.30.0.34) print "8cdb" as a return value of checkFramebufferStatus, but there's not enum in WebGL. Chrome, FF on same machines give "8cd5" which is FRAMEBUFFER_COMPLETE and Edge on Win10 (somewhat unexpectedly) gives "8cdd" which is FRAMEBUFFER_UNSUPPORTED.
<rdar://problem/31653690>
works now