Open existing project takes a folder into the list in which Quartz is already set up. It is meant for two cases: a project once created by hand, and one that comes from another machine.
What QuartzControl checks
Exactly one thing: whether a quartz.config.yaml lies in the chosen folder. If it is missing, the
row says “Not a Quartz project”, and the project’s areas stay empty.
That can have two causes. Either it really is not a Quartz project — or it is one in which the setup step never ran. A freshly cloned Quartz does not bring the file; it comes about at creation time.
What QuartzControl does not do
It changes nothing. An added project is read, not rebuilt. No file is created, no folder switched, no setting overwritten. Only when you save on a page does anything get written.
It installs nothing. If the project comes from another machine, node_modules is missing as a
rule — that does not belong in a repository and is not
shipped. The first build reports it. The built files of plugins installed from a source are missing
too; those are fetched back under Plugins.
From a second machine
The usual route: the project lives in a repository, is cloned there and added here. What is missing and how to get it back is in 6.3 – Git sync.
One point that surprises people: snapshots do not travel. They live in the project but belong to this machine and this copy — on the second machine the list is empty.