I'm able to post messages to Miiverse without a problem, but whenever I try to attach a screenshot, it returns this message:
"Error Code: 121-9998
Could not connect to the Internet. Please check your network connection and try again."
When I search for that error code at nintendo.com, it says it's unable to find it or something like that. I don't think it's actually my connection, since everything else seems to be working fine. Any suggestions?