I have a Fury R9 on ubuntu-based linux running on a 4.11 kernel. The last driver version that i was able to install without problems is 17.10.
Both 17.30 and 17.40 have drivers integrated that were build against xorg-server-core 1.19 but ubuntu 16.04 ships with version 1.18.
The result of installing them on my system is that on startup the xserver stops with an ABI error. Suppressing these errors lead into a segfault.
I tried to upgrade the xserver to 1.19 and the desktop come up fine but then it seems that vulkan is not running properly anymore(which is my reason to install amdgpu-pro).
In an older post i found a reference from release notes that 17.30 does not support newer kernels, but in the current release notes is nothing of the sorts. Does this still apply?
What is the setup of your test system exactly? Kernel and xorg version.
EDIT: Ok i found out that with 16.04.3 came HWE which needs to be enable manually on older installations which gives you then xorg 1.19. Could you mentation that on the install instructions for ubuntu.
And last but not least. The reason i try to update is because i'm playing DOTA2 and the new vulkan client requires the "VK_KHR_maintance1"
extension from the vulkan driver. Is this available in 17.40?