FTB has issued an update to the Beyond server, but we have NOT updated yet. Please use version 1.6.1 until you see an announcement here or Discord that we have updated. Thanks!
Edit (5 hours later):
We have now updated to the recommended version (1.7.0) - See you soon in game!
Additionally, we have reset the End and the Nether. The /warp blaze is down temporarily, should be back up within the day. :)