Complain to NVidia. They broke something in the newer drivers that causes the problems in LR. Won't be the first time something like this has happened. If you're on a Mac you don't have the option of using any other drivers for any of the hardware other than what Apple supplies with the OS. So I suggest you Get Over It and either use the GPU drive that is compatible with LR or turn the GPU feature off and use the newest drivers available.
... It is a disgrace to work without GPU in LR.
Why? I've been working without GPU support for long time and have no problems. LR works stable with a acceptable performance.
I second the above reply. I have a 5+ year old desktop that is using a NVidia GPU that LR says is supported. I turned it off after about a week of installing LR 2015. I've had no problems with it turned off.
I don't think it is acceptable if you know how it was before. Editing, merging and even import files (create preview files) is much slower without gpu. With an Intel Core i5 6600K and Nvidia GeForce GTX 980Ti the difference is insane. In fact I don't care if it is a Nvidia or Adobe problem. What bothers me is the fact, that neither Nvidia nor Adobe announced something in their release notes. And also it is not possible to contact Adobe if you are a "normal LR" user who purchased a single LR license. Sure I can work without gpu but it is a huge difference. And if Adobe offers the feature it should work at least without using a driver that old.