The Render button is locked

The line above the button names its reason: voices not synthesized yet, the music bed still preparing, or clip lengths still being measured. Each guard protects a sample-exact file. Do the named step and the button opens.

Check: the readiness line directly above the Render button names the reason (the button's own label never changes; the line does). The common ones: the script has no synthesized voices yet (Voices phase), the music bed is still preparing after a pick or restore, or clip lengths are still being measured.

Fix: do the named step. Each guard makes sure the complete mix is ready before rendering starts. As a guest, rendering comes with the free account; everything you set up carries over when you sign up.