Working on the translation. Google Translate below:
⚠️ Due to unforeseen complications on the part of the certificate issuer, we will be forced today, October 26, 2020 from 1:00 pm, to temporarily replace the Sincoolka (5G) Wi-Fi authentication certificate with a completely different one, issued by Let’s Encrypt.
Because many devices are set to trust other authorities, connection issues are likely to occur. We apologize for them and offer a procedure on how to solve them:
Android:
Paradoxically, the devices with our Sincoolka Wi-Fi application are the worst off. It offers a high level of connection security, but prevents connections to our network with a new authority.
We will try to release an update in the near future to address this. In the meantime, from 13:00, the network set up in this way must be removed and set again manually.
Windows:
If you receive a “Cannot connect to this network” message, remove the network from the system:
- Click on the network icon in the lower right corner.
- Right-click on the Sincoolka network (5G) and select Forget.
You can then reconnect. If you have trouble connecting to the Internet afterwards, be sure to set the random hardware addresses for the Sincoolka (5G) network to Off.
If you receive a message that starts with “Continue connecting?”, Press “Connect”. Windows should show ISRG Root X1 as the authority, or DST Root CA X3, with the host name radius.sin.cvut.cz.
iPhone, iPad:
You will be faced with the choice of trusting the certificate from the ISRG Root X1 authority, or DST Root CA X3, named radius.sin.cvut.cz. In this case, you can continue the connection.
For Linux:
Download the Let’s Encrypt CA certificate (DST Root CA X3) to replace the current CA certificate. If you are using NetworkManager, use nm-connection-editor to edit the network connection.
In case of problems or other questions, do not hesitate to contact us by e-mail or other channels. Thank you for your patience.