At the Confluence code (in our scenario, during upgrade), we do validate all the connectors configured at 'Server.xml'.

During the upgrade task, the Confluence startup threw an Error -

Confluence had problems starting up”, but in this case there is a button saying “ignore these problems and start up anyway” 

• Above Warning/Error only visible to 'Admin' users. 
• Non-admin users don't get that warning or the option to "ignore these problems and start up anyway.” They can't proceed and see the same screen as 'Upgrade in progress'.
• In Multinode, it would again cause an issue if a non-admin connected to a different Node than the 'Admin' user has skipped the warning.

Expectation:
We should ignore the Warning/Error if one of the connectors has maxThread>=48. We should not validate all the configured connectors.