Cannot Login into KSC Web Console after KSC 15.1 Upgrade

[Tahmeed702]

"Authentication failed." "The username or password is incorrect." The error occurs after upgrading KSC from 14.2 to 15.1 in Web Console; we are entering the correct login credentials, but it is not logging in. I tried reissuing the certificate, then reinstalling and repairing it, but I was unable to resolve the issue. Screenshot attached 

I found a guide, but I don't understand how to do it. https://support.kaspersky.com/ksc/15.1/troubleshooting/other/15964#block8

If anyone solved it please help me to solve , with necessary instructions . 

 

 

 

 

[Demiad]

@Tahmeed702 hello

1. Do you have many managed devices on this KSC server, or is it just a test environment?

2. Could you tell me what signature hash algorithm and key length you have now?

Open: C:\ProgramData\KasperskyLab\adminkit\1093\cert\klserver.cer