Koffie

If you haven't migrated your account before the big maintenance you will have to wait for a future maintenance (maybe the next one? I dunno).
I have the same error message with my other account which I migrated yesterday, my first account that I migrated before 10 November already works.

Hello Maplers,
Please make sure to accept both the service migration and the MapleStory game migration in order to begin playing on November 10th. If you miss your chance now or wait until after November 9th to migrate, you'll have to wait for an upcoming maintenance in order to access the MapleStory world in Europe.

Source: http://forums.maplestory.nexon.net/discussion/3594/maple-memo-global-migration-update/p1

And question 6 on the micro site says this:

6 What happens if my game has been migrated to the Nexon Launcher and I didn't create a Nexon Global Account in time?

Once your game has migrated to the Nexon Launcher, you will receive a notification upon logging into the Nexon Europe Launcher. You will still be able to set up your Nexon Global Account and upgrade the Nexon Europe Launcher to the new Nexon Launcher but will not be able to play on the Europe server until your Maplestory Europe gameplay data has been transferred. The Maplestory Europe gameplay data will be transferred periodically after November 9, 2016. You will however be able to play on the North America server in the meantime.

Source: http://maplestory.nexon.net/micro-site/ems

Good to see some progress, I hope the download and play block issue will be resolved soon as well. And I hope the other games will be unblocked on Steam as well, (Mabinogi for example was accessible after European version closed, then they mysteriously blocked it, and now it's still blocked.) I mailed GabeN about this issue as well, but he hasn't gotten back to me yet.