This happen to me on Ubuntu 16.04.1, on Firefox 50.1.0, running it on CLI randomly (couldn't find any pattern) crashes with "intel_do_flush_locked failed: No such file or directory".
Asus UX303UB
uname -sir: Linux 4.4.0-59-generic x86_64
product: HD Graphics 520
vendor: Intel Corporation
configuration: driver=i915_bpo latency=0
This happen to me on Ubuntu 16.04.1, on Firefox 50.1.0, running it on CLI randomly (couldn't find any pattern) crashes with "intel_ do_flush_ locked failed: No such file or directory".
Asus UX303UB
uname -sir: Linux 4.4.0-59-generic x86_64
product: HD Graphics 520
vendor: Intel Corporation
configuration: driver=i915_bpo latency=0