We noticed an issue with Virtual ports created by the Serial Device Configuration Utility don't have valid digital signatures in windows 10. This stops communication of the serial server with the field devices.

Here are the methods to overcome this issue:

Method 1:

Update the EKI Device Configuration Utility to v3.0.2.5  from the following link (You will have to remove the virtual comm ports from the old utility first).
 EKI series Device Configuration Utility V 3.0 

If this doesn't resolve the issue. Carry out the next method.

Method 2:

Go to Bios & disable Legacy support & Secure Boot options. Select Save & then Exit. The PC will restart.

Execute Command prompt as administrator & enter the following commands:

bcdedit.exe -set loadoptions DISABLE_INTEGRITY_CHECKS

bcdedit.exe -set TESTSIGNING ON

Then restart the PC.

This will disable the digital signature enforcement permanently & the field devices will start communicating with the serial server.