SIMATIC WinCC Open Architecture Forum

Hi everyone,

We have a project developed i the version 3.15. Today the certificates expired, so to fix it quick we copied the certificates dfrom verions 3.19, as advised in winccoa help.
But since we did that chamge the desktop ui can't conect, we get the "could not get server version" error message.

How can we fix this?

Thank you very much

1.
When they expired today it must be the mxProxy certificates, which means the following files.
host-cert.pem
host-key.pem
root-cert.pem
(but you must use all new ones because of the new root-cert.pem; just if you copied the ones for the DesktopUI and missed the mxProxy ones)

2.
Did you restart the mxProxy or project?

3.
Try to delete the (files from the) cache folder on the clients:
C:\Users\<username>\.wincc_oa-cache\<project name>\
(should not be neccessary but try to be sure)

4.
Did you maybe add the certificates to the Windows Certificate store and use the "wincert" option?
Then you must update the name/thumbprint in the config.

Hello ,
I have the same problem on a DRS 2x2 System. Because it is complicated i transfer the certificates from 3.19 at one of my Servers.
I delete the wincc_oa-cache folder from one of my Desktop UI Clients and it work, the client connect to this Server.
I have stil problem at DRS Connections betweet servers (i thing because of Mxproxy Cert expiration) and also this message apears at the log :
Certificate /C=AT/ST=AUSTRIA/L=EISENSTADT/0=ETM professional control/CN=ETM CA verification failed, due to: self signed in certificate chain.

The best solution would be to create your own certificates. Have a look at the help and the security guidelines:
https://www.winccoa.com/documentation/W ... nel_2.html
https://www.winccoa.com/downloads/detai ... -v319.html

Additionally please note the related certificate post on our website:
https://www.winccoa.com/news/detail.htm ... eb7cfcc6ff

Below are some options with the most recommended option first:
1. Exchange the default certificates with your own ones

Br, Herbert

Hello,

The issue is has been resolved (most likely temporarily) by using the Certificates from 3.19 Version at 2x2 Servers.
I believe there is no problem using this certificate but as i understand it is not recommended for security reasons, is that correct?

Thanks a lot..

You can use those certificates from ETM for test purposes, but it is not allowed to use them for real plants:

"To make newly created WinCC OA projects (using certificates) run "out of the box", we deliver standard certificates with the product. For real plant projects the use of these certificates is not allowed and own project specific certificates must be created!"
[https://www.winccoa.com/documentation/W ... asics.html]

Br, Herbert