Solutions are on there way, according to community manager Marcin Momot.
If you’d like to check which problems are most common with the new DLC, or look for workarounds and DIY solutions, be sure to check out our Errors & Problems in Blood and Wine guide. There are many of them, ranging from performance troubles, to disappearing diagrams and tail-less horses.
We're working on the next patch and hoping to have it out as soon as possible. Should address all major reported issues.— Marcin Momot (@Marcin360) June 6, 2016