Execution could not continue error: GZDoom v.4.1.0

[GothicGold]

Updated Gzdoom to ver. 4.1.0 today and I keep getting the same message whenever I try opening anything:

Execution could not continue.

Unable to load shader Default:
Init Shader 'Default':
Vertex shader:
Vertex shader was successfully compiled to run on hardware.

Fragment shader:
Fragment shader was successfully compiled to run on hardware.

Linking:
Vertex shader(s) failed to link, fragment shader(s) failed to link.
unexpected error.
unexpected error.

I'm only trying to open ultimate doom so I know there shouldn't be any compatibility issues there and I have also tried both drag-n-drop and directory methods to open them WAD, both resulting in the same error. I tried using Doom II as well and the same errors occurred so it isn't the WAD's error. All of my wads use to work months before so I really have no idea what may be the issue here.

My laptop's specs are:

• OS:Windows 7 Home Premium 64-bit (6.1, Build 7601)
  Processor:AMD A6-4400M APU with Radeon(tm) HD Graphics
  Memory: 4096
  Graphics Card: AMD Radeon HD 7520G
  OpenGL version: 4.2
  Directx version: Directx 9, 11.o
  Vulcan: not available

Any help would be greatly appreciated!

[Rachael]

Try "+vid_enablevulkan 1".

If that doesn't work, what version did it stop working? Does 4.0.0 work? 3.7.0? The vintage 3.8.0?

[_mental_]

According to this and this Radeon 7520G doesn't support Vulkan.

[GothicGold]

I've reverted to vintage 3.8.0. and it is working now! I find that very strange as 3.7.0/3.7.2 didn't work either but regardless, thank you for the help! Must be the recent addition of vulcan that broke the 4.X.0 releases on my laptop

[XxMiltenXx]

If 3.7.2 didn't work either, it's not the Vulkan implementation that's causing problems for you. The proplem is rather, that AMD doesn't release any new drivers for your graphic card. The latest I could find was from 2015. If you don't have that driver yet, you can try updating and see if that helps.

[Graf Zahl]

It is really too bad that AMD so often leaves users hanging with broken drivers. "Unexpected error" literally means that the driver threw up on something that should work by the specs, and it's not the first time this happened. The entire batch of OpenGL 3.x cards (Radeon 3xxx - 5xxx series) is utterly useless for anything running an OpenGL core profile due to having their drivers abandoned while still being buggy.

That aside, if the card reports OpenGL 4.2, chances are that the driver is not the most recent one. This card should have GL 4.5 support with its latest driver.