A customer asked me this morning..."why can't I publish from my project? all the publish buttons are disabled."
The most common cause of not being able to publish from a project is there is some form of error in the project. Even if the error is in a step after the lens/publish point, the project will disable all publish buttons until the error is resolved.
To resolve, look through your Steps Editor / Steps Panel. Do you see a red exclamation point? The project must have no red exclamation points in order for the publish buttons to be enabled.