My selfsignedcertificate expired in 1949

[MarkLittell]

On February 22 this year, I uninstalled ArcGIS 10.3 or 10.4, I then installed 10.5

When I try to connect to it via Catalog or ArcMap, I get warnings the certificate is not valid. I am able to connect to it, it's just annoying clicking Yes three times. Every time.

I've discovered it expired in 1949.

Here is what it says from the admin / machine / [machine name] / sslcertificates / selfsignedcertificate

Valid from: Wed Feb 22 21:07:15 EST 2017 until: Sat Dec 31 21:07:15 EST 1949

Do I create another one, or is there a simple way to update the existing ?

Thanks

 - Mark 

[JonathanQuinn]

I don't think you can edit existing certificates, so the safest approach is to create a new one through the Admin API.