Error 500 after 19.3 migration?

Hello @rikudou@lemmings.world, I hope you are doing well.

We just updated our instance (https://jlai.lu) to 19.3 yesterday, and noticed that today the scheduled posts had disappeared. I tried to create them again, but got this error:

Just wanted to report this to you, let us know if at some point you are able to fix it.

Have a good one!