I'm trying to join a Flowdock group and it says it's full
Can you let us know what exactly you mean by joining a Flowdock group ? If you could show us what exactly you're doing in a form of screenshots (including the problem) we'd be able to help you better.
We do have Custom Groups in Flowdock however I don't think that's what you're referring to.
Thank you !
I'm not familiar with a limitation that can be placed on the number of members that a flow can have.
That being said, I'm wondering if the flow you're trying to join belongs to a different organization that might be maxed out on its user licenses. Does that sound like a possibility?