Mozilla Firefox 84.0.2，Windows 10
没有附加组件/扩展。Microsoft Edge 上也会出现这种情况。
输出curl -vvvvv https://addons.mozilla.org/：
* Trying 44.239.254.46...
* TCP_NODELAY set
* Connected to addons.mozilla.org (44.239.254.46) port 443 (#0)
* schannel: SSL/TLS connection with addons.mozilla.org port 443 (step 1/3)
* schannel: checking server certificate revocation
* schannel: sending initial handshake data: sending 189 bytes...
* schannel: sent initial handshake data: sent 189 bytes
* schannel: SSL/TLS connection with addons.mozilla.org port 443 (step 2/3)
* schannel: failed to receive handshake, need more data
* schannel: SSL/TLS connection with addons.mozilla.org port 443 (step 2/3)
* schannel: failed to receive handshake, SSL/TLS connection failed
* Closing connection 0
* schannel: shutting down SSL/TLS connection with addons.mozilla.org port 443
* Send failure: Connection was reset
* schannel: failed to send close msg: Failed sending data to the peer (bytes written: -1)
* schannel: clear security context handle
curl: (35) schannel: failed to receive handshake, SSL/TLS connection failed
答案1
事实证明，政府因为代理和 VPN 插件等原因封锁了该网站，但现在不再封锁了，因为封锁整个插件网站会扰乱工作。