Upgrading from 7.12.3 to 7.12.5 it give ERR_HTTP2_PING_FAILED

upgrading from 7.12.3 to 7.12.5 it give ERR_HTTP2_PING_FAILED after waiting long time, with chrome. I should adjust the issue on the browser side or on the fastcomet server? my line is slow, about 0.6 mbps upload…

I skipped the issue connecting with mobile phone and then it was upgrading perfectly.