Unexpected exception during gather of site <sitename>: Unexpected HTTP response: 404

Hello.
I was doing BigFix server migration from one server to another, after migration everything looks ok, endpoints are connected, fixlets running properly, but i see those errors from topic in GatherDB.log for every enabled site , and server is not gathering data. When i enable new site, no fixlets show up, and site version remains 0.

I also see warnings:

Mon, 31 Jan 2022 16:25:16 +0100 - Main Thread (2640) - Successfully read server signing key
Mon, 31 Jan 2022 16:25:16 +0100 - Main Thread (2640) - Successfully read client CA key
Mon, 31 Jan 2022 16:25:16 +0100 - Main Thread (2640) - class NoSuchGatherSiteID
Mon, 31 Jan 2022 16:25:16 +0100 - Main Thread (2640) - WARNING: Key APIServerKey doesn’t exist in the database.
Mon, 31 Jan 2022 16:25:16 +0100 - Main Thread (2640) - WARNING: Key PlatKey doesn’t exist in the database.
Mon, 31 Jan 2022 16:25:16 +0100 - Main Thread (2640) - WARNING: Key WebUICAKey doesn’t exist in the database.
Tue, 01 Feb 2022 08:22:14 +0100 - LicenseUpdater (7976) - HTTP gather for http://gatherer.bigfix.com/cgi-bin/LicenseServerFrontend.pl was successful. HTTPS connection to {https://gatherer.bigfix.com/cgi-bin/LicenseServerFrontend.pl} was unsuccessful due to {HTTP Error 28: Timeout was reached}; retried using HTTP

althought i followed steps from:

https://bigfix-wiki.hcltechsw.com/wikis/home?lang=en-us#!/wiki/BigFix%20Wiki/page/Server%20signing%20key%20Tool

Can someone advise how to make gather service work properly?

Failing on HTTPS but working on HTTP implies there may be a problem with your proxy configuration? It could be that your new root server is not using the same proxy or credentials as the old one, or perhaps your proxy server had specific rules allowing the old server to connect while not allowing the new one?

From the server, you should be able to connect to https://gatherer.bigfix.com/ and see the message “It Works”.

For thoroughness, you might try using Curl to connect to the site as well, which should ignore any per-system proxy configuration that might be in force transparently for your browser
C:\Temp>curl https://gatherer.bigfix.com/
<html><body><h1>It works!</h1></body></html>

Hello Jason.
Settings under BESAdmin /setproxy are the same as on old server.

From server i can connect to https://gatherer.bigfix.com and http://gatherer.bigfix.com only when proxy ip and port is enabled in IE. If not, than i cant reach those pages (http and https both).

When i try to: curl https://gatherer.bigfix.com/ (http and https both)
curl: (28) Failed to connect to gatherer.bigfix.com port 443 after 21028 ms: Timed out

Ok I suggest you should open a support incident to get some live help. It would be difficult to go back and forth here in the forum.