SIMATIC WinCC Open Architecture Forum

Hi,

I'm having problems with remote UI connections to server running WinCC OA v3.15 P017. The Redundant project is working for 4 years and this problem has never happened before. Since a couple of months, operators are reporting that sometimes when they close the Desktop UI, they cannot open it again later. When this happen, I find out that the control manager running the webclient script is at status 3. If I kill the manager and turn on it again, the problem is solved, but a few days later, operators report the error again. The log files indicate this:

WCCILpmon (1), 2023.12.20 05:40:39.414, SYS, WARNING, 36/pmon, Blocking Manager WCCOActrl(2) detected. No heartbeat since 30 seconds.
WCCOActrl (2), 2023.12.20 05:40:40.892, SYS, SEVERE, 141, Connection to client ::ffff:10.11.15.128 could not be encrypted:
WCCOActrl (2), 2023.12.20 05:40:40.894, SYS, SEVERE, 141, Connection to client ::ffff:10.11.15.128 could not be encrypted:
WCCILpmon (1), 2023.12.20 05:40:40.940, SYS, WARNING, 39/pmon, Manager WCCOActrl(2) is no longer blocking.
WCCOActrl (2), 2023.12.20 05:40:40.942, SYS, SEVERE, 141, Connection to client ::ffff:10.11.15.128 could not be encrypted: sslv3 alert certificate unknown
WCCOActrl (2), 2023.12.20 05:40:40.950, SYS, SEVERE, 141, Connection to client ::ffff:10.11.15.128 could not be encrypted: sslv3 alert certificate unknown
WCCOActrl (2), 2023.12.20 05:40:42.363, SYS, WARNING, 54, Unexpected state, HTTPServer::readMessage, ::ffff:10.11.15.128, Connection reset by peer (10054)
WCCOActrl (2), 2023.12.20 05:40:55.378, SYS, WARNING, 54, Unexpected state, HTTPServer::readMessage, ::ffff:10.11.15.128, Connection reset by peer (10054)
WCCOActrl (2), 2023.12.20 05:40:57.070, SYS, SEVERE, 141, Connection to client ::ffff:10.11.15.128 could not be encrypted: sslv3 alert certificate unknown
WCCOActrl (2), 2023.12.20 05:40:57.077, SYS, SEVERE, 141, Connection to client ::ffff:10.11.15.128 could not be encrypted: sslv3 alert certificate unknown
WCCOActrl (1), 2023.12.20 05:41:44.484, CTRL, INFO, 0, , Cyclic updateUserGroups running every 60 minutes.
WCCOActrl (2), 2023.12.20 05:42:21.243, SYS, WARNING, 54, Unexpected state, HTTPServer::readMessage, ::ffff:10.11.15.128, Connection reset by peer (10054)
WCCILpmon (1), 2023.12.20 05:42:53.031, SYS, WARNING, 36/pmon, Blocking Manager WCCOActrl(2) detected. No heartbeat since 30 seconds.

Could you help us?

Thank you,

If you did not do any update within WinCC OA lately and also no OS update, it could be related to expired, invalid or untrusted certificates:

"The message section that says "sslv3 alert certificate unknown" usually refers to the intermediate certificate in a chain of certificates. That certificate is expired, invalid or not trusted by one or more systems involved in the SSL/TLS communication."

Br, Herbert