Are you unable to like anything, or just the first post in a topic?
To clarify, here is what I see on an example Python topic:
No, I can't like anything at all. I can vote, but not like.
Odd, even in my secondary (non-moderator) account I can like posts in #python. Could you post a screenshot?
It's working now. I'm still not certain what went wrong, but as usual, leaving it alone seemed to help.