Today I received the following email from Twitter:
Application suspension notice
Hello,
This is a notice that your app - Discourse API - has been suspended from accessing the Twitter API.
Please visit developer.twitter.com to sign up to our new Free, Basic or Enterprise access tiers.
More information can be found on our developer community forums.
Regards,
Twitter Developer Platform
Does anyone know what this is about?
+++ Update +++
Looks like a widespread problem.
Hopefully at some point the Discourse developer team can come up with a sustainable solution to the Twitter problem so that a Twitter App & API is no longer necessary for every single forum owner.
I think the idea is to charge people for accessing Twitter data via the API, but it seems that the oEmbed API allows embedding (using the URL of an existing tweet) at no cost: