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FAQ & Troubleshooting


How do I contact Knald Technologies?

You can reach us via e-mail at the following addresses:

Or join us on the following social networks/sites:

What are the system requirements for Lys?

Please see the System Requirements page for more information on the minimum and recommended system requirements for Lys.


Activation Issues

Lys periodically requires an active internet connection in order to contact our license authorization servers. This check is preformed to ensure that your machine is authorised to run Knald and once license authorization has been confirmed you can continue to run Lys off-line until you wish to update the software (when an update is released)

Which ports and/or address does Lys need access to?

To ensure that the authorization servers can be contacted please configure your network so that the following addresses and ports are assessable from any machines Knald is installed upon.

Many studios and university networks sometimes block the ports required for Lys's license/authorization process - please contact your network administrator to ensure the required ports are open and any proxy servers are not blocking HTTPS traffic for the above addresses.

What happens if I don't have access to the internet?

Following the initial activation, Lys will re-authorize with our servers whenever the application is launched. If Lys is unable to communicate with our servers during startup, it will allow up to a 30 day grace period before authorization is required for use.

Lys isn’t working correctly. What can I do to fix the issues I am having?

Here are some things you can try that might help you out:

  • Ensure you have a compatible graphics card and that your system meets the minimum requirements. Lys requires an OpenGL 4.3 compatible GPU. If your GPU was made after 2012, there is a good chance it is OpenGL 4.3 compatible. GeForce 400 Series and newer & AMD/ATI Radeon HD 5000 Series all support OpenGL 4.3.
  • Check that you have the latest drivers for your GPU. Many issues can be resolved by simply installing the latest drivers for your graphics card. You can get the latest Nvidia drivers here and the latest AMD/ATI drivers here.

Driver Issues

Some NVIDIA drivers have been reported to cause problems with OpenCL/OpenGL. Please do not use the following drivers with our software as they are unsupported by us.

Knald Unsupported Drivers
  • 344.11
  • 344.48
  • 344.60
  • 344.65
  • 344.75
Lys Unsupported Drivers
  • 364.51
  • 364.72
  • 365.10
  • 365.19
  • 368.22

Installing new drivers

On some occasions errors within Lys are due to cached shaders that the driver hasn't compiled correctly or are corrupted in some way. Whenever you install a new driver we always recommend that you perform a clean installation and delete any cached shaders if they are present on your system.

Performing a clean installation of your drivers and deleting shader cache is simple and you can learn how to do it on the Clean Driver Installation page

If you are still having issues, please contact us! You can reach us via e-mail at:

Machine Virtualization

We are unfortunately unable to support any kind of virtual machine for use with our products. This is due to GPU driver functionality and hardware acceleration being severely limited in such virtualization scenarios.

I can run other 3d programs on my virtual machine. Why doesn't Lys work?

When using a virtual machine the sandbox does not have direct access to the GPU via direct passthrough and as such resorts to GPU emulation which gives the ability to run some 3d programs.

In addition, GPU hardware vendors often restrict direct passthrough functionality on consumer GPUs, which would be a prerequisite for any compute program running within a virtual environment, preferring to keep that functionality for workstation graphics.

Please see the minimum requirements for more information on the minimum and recommended specifications required needed to use our products.

How do I submit a bug report & what information should I provide?

When submitting a bug report to us you will need to include a minimum of the following:

  • Name & build number of the program you are reporting
  • Operating system version
  • Graphics card model & VRAM amount
  • Currently installed GPU driver
  • System information (a DXDiag report is often easiest)
  • A zipped copy of the Logs folder found at %username%/AppData/Local/Knald Technologies (This contains crash logs and information).

An example bug report might look similar to the following

  • Lys 1.0.1, Build 20160313001
  • Windows 10 Pro 64bit
  • NVIDIA GeForce GTX 980 4GB VRAM
  • 361.43

Lys is running slowly/Image is not processing/the 3D Preview Window is blank

In the case of any of these issues, please check the following:

  • The amount of VRAM that your GPU has. The size of the image which Lys can process successfully is limited to the amount of VRAM that it takes to process, so using a very large image (4096² and above) may result in issues. Most modern graphics cards have at least 1GB of VRAM and therefore should be able to process a 4096*2048 texture with ease. If you have more than 2GB of VRAM, you should be able to process a 8192*4096² texture.

Below you will find a rough guide of how much contiguous VRAM is required on a single GPU in order to process the various texture sizes listed1)

8bit 16bit Int. 32bit Float
256*128 110MB 145MB 145MB
512*256 115MB 150MB 150MB
1024*512 120MB 170MB 170MB
2048*1024 155MB 240MB 240MB
4096*2048 290MB 500MB 500MB
8192*4096 810MB 1.5GB 1.5GB
  • Running multiple instances of Lys. Due to the amount of GPU VRAM required to process images within Lys., it is currently not recommended to run more than one instance of the program as VRAM may become exhausted. Rebooting your PC may free up stuck resources and can release VRAM which was being used by other applications and/or contended erroneously due to driver and/or application bugs.

Why are my exported textures failing to load after using Post Export Actions?

This error can occur (and is often coupled with a 'This app can't run on your PC' error) if the application your are trying to open the exported textures with is closed but still running in RAM from the previous time it was used. To check if this is the case please open Task Manager and ensure that any previous instances of the offending application are not already running & closing them where necessary.

1) As SLI/Crossfire and Dual GPUs on a single card do not have contiguous VRAM blocks you will only be able to access half of the advertised amount on such systems.
faq_lys.txt · Last modified: 2017/05/23 03:49 (external edit)