error 500 when trying to block some communities

I tried to block a couple communities from reaching my timeline and got the 500 error. These are the URLs the browser tried to visit when clicking the “block” button:

• https://fedia.io/m/castiron@lemmy.world/block
• https://fedia.io/m/humor@lemmy.world/block

I’ve had no problem blocking lemmy.world communies in the past. It’s just a problem today. And today I had no problem blocking communities on other Cloudflare instances (e.g. lemmy.zip) and non-CF instance lemmy.ml.