Unable to Create a Subscription
If you are unable to create a subscription for an order or process open orders the most likely cause is an issue with your settings.
If you’ve enabled the Delay charge in checkout setting you also need to enable the Allow unpaid subscriptions setting.
Explanation of the two settings:
Delay charge in checkout - the delay charge in checkout setting enables you to accept orders without charging the initial payment, that is, the initial payment is delayed and can be charged manually at a later point in time.
Learn more about delayed charge in checkout.
Allow unpaid subscriptions - typically you can only create a subscription for orders for which the initial payment has been charged. However if you work with the Delay charge in checkout setting, you can enable the Allow unpaid subscription setting if you would like to not only accept unpaid orders but also create subscriptions for these orders and charge the initial amount manually at a later point.
To enable this setting go to Settings > Subscriptions > CREATE SUBSCRIPTIONS > Enable the switch for Allow unpaid subscriptions.