(bug): Users are unable to subscribe to channels.

Summary

UPDATE: It's working again now for me a few hours later on 3/13/19. I was able to unsubscribe from the 3 channels I wasn't able to unsubscribe from by clicking "Subscribe" and then clicking "Unsubscribe" as one normally would.

I'm getting an error in Chrome/Win10 when I try to subscribe to channels:

If I refresh, the subscribe button looks like it hasn't been pressed but I am receiving posts from the channels I subscribed to:

If I visit those channels even in the mobile app the subscribe button still looks like it hasn't been pressed and I am unable to unsubscribe:

Other users are reporting this bug in H&S:

Steps to reproduce

1. Visit a channel you aren't subscribed to.
2. Click "Subscribe"

Platform information

Chrome/Win10

What is the current bug behavior?

I'm getting an error in Chrome/Win10 when I try to subscribe to channels. If I refresh, the subscribe button looks like it hasn't been pressed but I am receiving posts from the channels I subscribed to. If I visit those channels even in the mobile app the subscribe button still looks like it hasn't been pressed and I am unable to unsubscribe.

What is the expected correct behavior?

Clicking "Subscribe" should subscribe you to the channel, make it so the subscribe button looks like it's been pressed and should not produce an error message.

Relevant logs and/or screenshots

Possible fixes

(If you can, link to the line of code that might be responsible for the problem)