This plan is not available for checkout
Checkout session route rejected the selected plan (400 This plan is not available for checkout.).
Why this happens
Plan unpublished, not sellable, wrong id, or checkout disabled for that role. Related to Plan not found or checkout is not available (broader/premium client copy).
Diagnose and fix
1. Return to pricing; pick the plan again from Buy Premium / Premium Pro.
2. Admin: ensure the plan is published with a valid price under Plan & pricing.
3. Avoid stale bookmarks with old roleId / duration keys.
4. See Plan not found or checkout is not available.