Hi,
So these are the errors
[1] Unable to connect to the remote server
[2] A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond 10.100.15.121:443
You need to check if our OutSystems on-premise platform can reach this IP address.
You can use a ping, or telnet and try to connect, you can also install and use netchecker.
But as you already know it doesn't work I think you need someone responsible for the OutSystems infrastructure and someone of the external systems, to figure out what has changed such that the connection can not be made anymore.
Regards,
Daniel