Curl "https://localhost:52311" connection refused

curl "https://localhost:52311"
curl: (7) Failed connect to localhost:52311; Connection refused.
The last I changed was to created and implement a new cert for HTTPS access to ILMT web interface,

Try -k flag on curl as temp workaround.

If it works, you will need to sort out adding your cert bundle into curl.

Same results:
curl -k "https://localhost:52311"
curl: (7) Failed connect to localhost:52311; Connection refused

When I try to connect to BigFix console, I get the http Error 28 connection timeouts.

Is this on the BigFix Server? The most likely reason for the connection refused is that the BESRootServer server service failed to start, and if you just changed the certificate I would expect the certificate format, key format, or key password is incorrect or not configured correctly in the client settings.
Check the BESRelay.log on the root server for error messages.

@fhabibi
Sounds like your certificate update had some issues.
Recommend you open a ticket at https://support.bigfix.com for some focused help.

This is a BIGFIX - ILMT package
I agree, it appears to be a cert issue. I just don’t know how to fix that.

Here is the BESRelay.log
at, 05 Feb 2022 01:57:28 -0500 - /cgi-bin/bfenterprise/besgathermirror.exe/-siteversion (1495713536) - Unable to find site id for URL: http://cxxliem01p.xx.xxx.net:52311/cgi-bin/bfgather.exe/actionsite
Sat, 05 Feb 2022 02:01:59 -0500 - 1058989824 - HTTP gather for http://sync.bigfix.com/cgi-bin/bfgather/bessupport?Time=1644044518 was successful. HTTPS connection to {https://sync.bigfix.com/cgi-bin/bfgather/bessupport?Time=1644044518} was unsuccessful due to {HTTP Error 60: SSL peer certificate or SSH remote key was not OK: SSL certificate problem: unable to get local issuer certificate}; retried using HTTP
Sat, 05 Feb 2022 02:02:02 -0500 - 1058989824 - HTTP gather for http://sync.bigfix.com/cgi-bin/bfgather/ibmlicensereporting?Time=1644044521 was successful. HTTPS connection to {https://sync.bigfix.com/cgi-bin/bfgather/ibmlicensereporting?Time=1644044521} was unsuccessful due to {HTTP Error 60: SSL peer certificate or SSH remote key was not OK: SSL certificate problem: unable to get local issuer certificate}; retried using HTTP
Sat, 05 Feb 2022 02:02:28 -0500 - /cgi-bin/bfenterprise/besgathermirror.exe/-siteversion (1058989824) - Unable to find site id for URL: http://cxxliem01p.xx.xxx.net:52311/cgi-bin/bfgather.exe/actionsite
Sat, 05 Feb 2022 02:04:31 -0500 - Main Thread (3838875776) - BES Root Server received stop request
Sat, 05 Feb 2022 02:04:31 -0500 - Main Thread (3838875776) - BES Root Server shutting down

So that log ends with the service shutting down - do you get any messages in the log when you try to start the service again?
Agree, if this doesn’t start up when you start the service, a support ticket can help.