Ok I as well as others have been having problems posting to the Hives.
I think I figured out my issues and maybe yours.
You can't use the hive-100504 as a tag you will get this
This message will not clear until you clear out the whole post ( suggest you copy first) and do it again without the hive- tag..
To Post in the community go to that community page and click on New Post and post like always without the hive- tag your posting from the hive/community by default. After you post you will need to ReSteem it to send it to you follower list.
Hope this helps =)