Gateway/PBI Desktop weird behaviour

Hi All, I've installed Power BI Desktop on a server with a local SQL Instance so we can publish to bi.com using the gateway. When trying to add a custom column and entering a column formula it states "The formula is incomplete" with every formula added, even just '="a"' shows as incomplete. Works fine in other instances of Desktop but they don't have line of sight of the SQL database. Tried clearing Cache Cleared App Data directory Re-installed Upgrade to latest version UAC is off (but is has been run as an admin anyway) Tried a new report with a completely different data set Based on the above it would suggest something environmental, anyone have any ideas? Its installed on Server 2012 R2 Standard with the Enterprise Gateway installed.