On Wednesday 04 November 2015 20:05:21 Andrew Hutchings wrote:
First of all please see the caveats section of this post, you may need to alter your SSL configuration: https://www.nginx.com/blog/nginx-1-9-5/
If this doesn't fix it then it may be that Opera doesn't support NPN negotiation that is in OpenSSL 1.0.1 for HTTP/2. If you recompile with OpenSSL 1.0.2 it will use ALPN which is actually the standard for HTTP/2.
For now most browsers are supporting both negotiation types but this may change in the future.
Missing negotiation causes fallback to HTTPS, not errors.
wbr, Valentin V. Bartenev