Just did dist-upgrade to new versions of Raspian on my Pi 3. I started with fresh NOOBS and did upgrade. Chromium-browser now at V56.0.2924.84. When I try to start youtube it refuses to start and gives error: ERR_SSL_PROTOCOL_ERROR. Other google apps like gmail that use SSL do work okay. Also, this forum uses https: and that working fine, so the issue seems to be with chromium-browser
I was having other less serious errors on you-tube with chromium-browser V51 before the update. In my previous post on that I MISTAKENLY mentioned that I was running V56 on Ubuntu 16.04 (64bit) with no errors. In fact, I was running V55.0.2883.87, which is in fact still running fine. I mention that other post just in case someone was misled by that mistake.