That worked, thanks
It highlights two issues with the IDE though.
1. When you add a new source file to a document, it doesn't offer you an extension. It really ought to force you to use .agc
2. When you rename a source file, you have to right click on it, select
Remove From Project, the Open a file, right click on that and select
Add to Current Project
It's a bit of a farce.
Selecting multiple files at once and adding them to (or removing them from) the project would be nicer. As would the option to open a source file and have it put in to the project without further clicks.