Try to create lets encrypt and see this 
aaPanel v 6.2.8
try to fix It by clicking on "fix" link - nothing happend
tail -n 100 /www/server/panel/logs/error.log
Starting new HTTPS connection (1): acme-v02.api.letsencrypt.org
Unable to intialise client. error=init() got an unexpected keyword argument 'server_hostname'
::ffff:85.113.135.107 - - [2019-10-14 14:02:37] "POST /site?action=CreateLet HTTP/1.1" 200 370 0.050119
::ffff:85.113.135.107 - - [2019-10-14 14:02:37] "GET /static/layer/skin/default/icon.png HTTP/1.1" 200 12220 0.014105
::ffff:85.113.135.107 - - [2019-10-14 14:02:52] "POST /site?action=GetDnsApi HTTP/1.1" 200 773 0.021795
::ffff:85.113.135.107 - - [2019-10-14 14:02:58] "POST /site?action=CreateLet HTTP/1.1" 200 317 0.022971
Starting new HTTPS connection (1): acme-v02.api.letsencrypt.org
Unable to intialise client. error=init() got an unexpected keyword argument 'server_hostname'
::ffff:85.113.135.107 - - [2019-10-14 14:03:02] "POST /site?action=CreateLet HTTP/1.1" 200 370 0.052297
