@astrugatch Thanks, I can reproduce this.
Cause: since 1.5.10.2253 the server signs its HTTPS certificate with a “FOG Web CA” intermediate under the FOG Server CA. The client installer only accepts an HTTPS certificate issued directly by “FOG Server CA” when it downloads ca.cert.der, so the download fails and the pin fails. The fix is in the client: https://github.com/FOGProject/zazzles/pull/48. It needs a new client release.
Workaround until then, either one:
Trust the FOG CA before you install. Download http://<fog-server>/fog/management/other/ca.cert.der (plain HTTP works), then run certutil -addstore Root ca.cert.der as administrator. Then run the HTTPS install as before. Or install with HTTPS off. The client downloads the CA over HTTP, and the server redirects it to HTTPS after that.