Unable to post the blog on my website through a self hosted ghost page

[ikarus-akhil]

I have created a ghost docker image using the ghost:5 image as a base image, pushed it to ECR, and then deployed it using ECS. The image has been deployed to ECR since November 30 and I recently just updated my nginx image (which behaves as a reverse proxy) and then I ran the task definition again, but since then I have been unable to post my recent blog as it is freezing as soon as I click the publish button.
I am getting the following console error:

So then what I did was I checked the console logs of the docker image and got the following error:

[tianon]

That's weird -- is the newsletters behavior that appears to be erroring here built-in, or some kind of optional plugin?

(Missing a key seems like some database migration failed to run, but I'm 100% guessing.)

[ikarus-akhil]

I have not done any migration so it cannot be a migration error.

[ikarus-akhil]

So I was able to solve this issue by just making a new image of my application, which updated the ghost version in the image and the problem was resolved.