SEPM is configured to download updates from LUA server via HTTPS.
LUA server is configured with distribution center to be available via https:
SEPM is configured to get the content from this distribution center:
Once initiated download on SEPM it gives similar log:
LiveUpdate encountered one or more errors. Return code = 4. [Site: My Site] [Server: <server name>]
And download fails.
Check from SEPM server via IE browser access to corresponding distribution center URL for a file livetri.zip
Browser gives message that certificate is not trusted.
Export the certificate you see as not trusted in browser and add it as a trusted on the SEPM server system in Windows certificates store.