im also having problems with miiverse 3ds, but i have different message and different code. it says the security certificate has a problem. the error code is 012-1511. i click Allow, and it says communication error. i just wanna use miiverse
Console was unable to find the juxt-prod.pem certificate on your SD card. Try reinstalling Nimbus.
You can also try and look if you have modules and game patching enabled. Thats how I combatted my issue.