Please share the crash logs.
To know how to check logs, please check this article : Customer Support - How do I find event logs when a program crashes? | CyberLink
Faulting application name: lightroom.exe, versio: 188.8.131.52, aikaleima: 0x561477b9
Faulting module name: atio6axx.dll, versio: 184.108.40.20619, aikaleima: 0x50f5c14a
Exception code: 0xc0000005
Fault offset: 0x00000000006f91ad
Faulting process id: 0x1ed0
Faulting application start time: 0x01d105e886bd99e5
Faulting application path: C:\Program Files\Adobe\Adobe Lightroom\lightroom.exe
Faulting module path: C:\Windows\system32\atio6axx.dll
Report id: da92fbef-71db-11e5-b996-082e5f010ac4
As I can see this line : "Faulting module path: C:\Windows\system32\atio6axx.dll"
Please update the graphic card driver from AMD website.
Please download the autodetect utility of AMD and update that.
Here is the link : Download Drivers
No fix with updating graphic card.
It's legacy model (Ati firepro V4800) and didn't have any direct driver updates so i updated whole Amd control system to see if it helps. It didn't.
Disabling that did resolve part of the problem. Preferenses opened, but as you might know, usability went away.
So the problem is related to graphics card with no solution from Amd...
Uncheck the option Preferences > Performance > Use Graphics Processor. Then reenable the AMD display adapter reversing the instructions above. LR should then start.
For further details, see this help article: Adobe Photoshop Lightroom Help | Lightroom Graphics Processor Acceleration (GPU) Troubleshooting & FAQ.
It wasn't necessary to disable the display adapter -- you could have followed the instructions in the section Manually Disable The Graphics Processor.
The box must be unchecked, then LR works. At that part at least.