web portal for SupportCenter Plus is not working in browser Internet Explorer 11 and Firefox.

the message in Internet Explorer if "This page can’t be displayed" and the message in Firefox is: An error occurred during a connection to supportcenter.kibs.mk. SSL received a weak ephemeral Diffie-Hellman key in Server Key Exchange handshake message. Error code: SSL_ERROR_WEAK_SERVER_EPHEMERAL_DH_KEY

Version of the SCP is 8.0 build 8002 installed on Windows Server 2008 R2.