Chanklish

This product is garbage - beta software with no KB, no help, no support, and no response from ESET.
We are decommissioning this pilot on 2 of our clients because of too many issues and super, super long hold times from ESET.
Use version 5 - DO NOT deploy this ERA version.

Sounds like one of the servers behind a load balancer is providing an invalid OCSP response. I'm not having any issues opening the website but that's most likely because I've got a response from a server which provides a valid OCSP response or OCSP stapling is not used on the server (didn't check the SSL communication to find out).
Strange that you're getting a different result with Firefox and other browsers. Try reloading the web page in Firefox by pressing Ctrl+F5.

I can open this web site fine in FireFox.
It won't open at all in IE11. All I get is a blank web page. Ditto for Edge. However, Edge didn't show any Intermediate cert. in the cert. chain path. So something is wrong with the cert. validation path for this web site.

Per Quals SSL Server check, a chain path has an extra cert. in it. This status has caused past issues with Eset SSL/TLS protocol scanning:

Hello @Chanklish,
the migration paths are described at https://help.eset.com/esmc_install/72/en-US/migration_same_version.html 
so follow the one applicable in you case.
Peter

i received a reply now 
CASE:64149