Sage support
Sage support is not optional as far as I am concerned.
Line 50 is a total mess and the Sage Data Service is a nightmare with no proper technical documentation. I got it running over RDP but couldn't package it as an app and had to give the users a full remote desktop.
One gem from Sage support when they asked for the IP of the server when trying to fix a local client install. I gave them the host name... no that doesn't always work ? They couldn't tell me why and it didn't fix the issue. Reinstalling windows did though :/ how much are we paying for this again ?