Webclient control manager blocked

[VictorCalvo]

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,

[hpuchegger]

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