When you face such issues, you can follow the below steps to ensure you are not blocked. You need to make a parameter "false" in the configuration file as mentioned in below steps.

Steps to unblock:

1) Save all your projects and Close EPC (Very important step)
2) Check and confirm whether DigiCert Global Root CA certificate is available in the system. For that please follow below steps:

1. Press Windows+R  -> Then type certmgr.msc and click on OK
2. Certificate manager console will be opening and check whether the certificate is installed as mentioned in the below screenshot:

If you do not have certificate, please contact Schneider Electric Country Customer Care team
If you have the above certificate please follow the next steps to recover from the error.

3) Navigate to path:
C:\Program Files (x86)\Schneider Electric\Ecoreach V2\Package\Server
4) Find the file "EcoreachCore.exe.config"
5) Right click on this file and click "Edit" with notepad or notepad++
6) Change the following data(by default it will be "true", we are changing to false) :
<add key="ValidateCertificate" value="false" />
7) Save the file and close the file
8) Relaunch EPC application and try to generate QR code

These above steps should unblock you and if you still face any issues, please contact your country customer support team.