Translated by me:

Dear Readers, some time ago we have been informed that any and all licensing activities related to the "Log Horizon" series has been put on hold due to author's legal problems. At the same time, we couldn't share with You the reason of those problems or the fact of their existence itself until clarification of them at the source. According to newest assurances we received during and after the Frankfurt Book Fair the situation is already stabilizing. We slated the next volume of the LN in our release calendar for February/March

Source(in Polish)

Yes, I realize "newest assurances we received" sounds weird, but that's what they say. Also, they didn't say anything about Log Horizon:West Wind Brigade manga, which they're also releasing.