Changing subscription does not work

[stiofanoriain]

Bug report

Describe the bug

This is using Node.js and VanillaJS.

It is not possible to upgrade an existing subscription due to an IntegrationError.

To Reproduce

1. I have signed up for the basic subscription and can see it is active in my account.
2. I go to change-plan.html. Immediately the following error appears in the console:

[Error] Unhandled Promise Rejection: TypeError: null is not an object (evaluating 'subscriptionsDiv')
(anonymous function) (account.js:9)
asyncFunctionResume
(anonymous function)
promiseReactionJobWithoutPromise
promiseReactionJob

3. I select the Premium plan, enter credit card details and click Subscribe. The following error appears in the console:

[Error] Unhandled Promise Rejection: IntegrationError: Invalid value for stripe.confirmCardPayment intent secret: value should be a client_secret string. You specified: null.
k (v3:1:54498)
(anonymous function) (subscribe.js:46)
asyncFunctionResume
(anonymous function) (subscribe.js:41)

4. Nothing happens (no new subscription is created) and I am stuck on the credit card screen.

Expected behavior

The plan should upgrade and there should be proration.

System information

• OS: macOS
• Browser: happens in all browsers
• Server environment: Node