I initially took up this discussion with AMD but they seem to have become uninterested (or I don't have the right contact) and are pointing me back to Adobe.
I first noticed this while while running a Radeon R7 260X video card but did not immediately attribute it to the firmware update. The card had been running fine and then all of a sudden Lightroom started crashing in Development mode. Disabling the GPU did fix the problem, as suggested in several forum responses on similar inquiries. It fixes it in that it stops the crashes from happening. While I've seen this suggested as the "FIX", I see significant performance degradation with the GPU disabled so I do not consider this an acceptable fix but rather a debug step to isolate the problem to the GPU.
Thinking I may have needed an updated video card I purchased and installed a Radeon RX 470 RS. This is a fairly current technology and a huge step up from what I had. This card then also failed in the same way, until I finally downgraded the video driver and it started working again. (I have also seen another person in the forums with this same experience.) The latest drivers from Radeon do NOT work and LR will crash in development mode. I back-leveled the driver to a Feb 10, 2017 version and then LR runs fine with the GPU enabled. I can confirm that the GPU is being utilized because the performance difference is obvious, and I hear the fans on the GPU card kick up in speed when when moving sliders back and forth in the development mode.
I suspect this is an AMD driver issue more than Lightroom software, although it could also be a LR software issue that is exposed by a change in the latest AMD drivers. Problems like this often require cooperative debug effort from both sides. Unfortunately I don't have good contacts from either company and support from AMD seems to be taking the "Not my problem" attitude. Maybe it isn't their problem, but I'm trying to get them to give me some idea of what changed as that may be helpful in understanding why LR started failing. So far, no luck.
Windows 7 Pro 64bit
Intel i7-4790K Quad-Core 4.0GHz
32GB of memory
Program disk is a 256GB PCIe Gen 3 SSD
Data disk is a RAID 0 volume with two 2GB SATA3 HDDs striped for performance
Lightroom Vers 6.10
Video card: XFX Radeon RX 470 RS
Drivers tried that fail: (as reported by the windows Device Manager after installation)
18.104.22.1682 from the new 17.5.2 installation package also fails
Driver that runs fine:
21.19.519.2 (2/10/2017) - from the "17.2.1-feb28" installation package.
AMD's last suggestion to me was to back level to the 16.11.5 Crimson driver package.
Although I am now up and running fine with GPU enabled using the down-level driver, there is obviously a problem ... whether it be with the Lightroom software or the AMD driver. I would hope one or both parties would be interested in figuring this out and fixing it. Otherwise it gives both Adobe Lightroom and AMD Radeon a bad name. There are other photo image processing programs that are gaining popularity and there is also other popular video cards. I'd rather work with what I know and have at this point. Any help would be appreciated.