MATLAB2023a GUI Fails to Launch (MATLABWindow Error, Exit Code 127 on Ubuntu 22.04)

I'm running MATLAB 2023a on Ubuntu 22.04, and I keep getting the following error when trying to open any GUI-related function:

Error using open
MATLABWindow application failed to launch. Unable to launch the MATLABWindow application. The exit code was: 127

Warning: MATLAB has disabled some advanced graphics rendering features by switching to software OpenGL. For more information, click here. 
MathWorks::System::IUserException in WebControllerFactory::create(): [Error using matlab.internal.cef.webwindow
MATLABWindow application failed to launch. Unable to launch the MATLABWindow application. The exit code was: 127

Error in matlab.internal.webwindow/createImplementation (line 319)
implObj = matlab.internal.cef.webwindow(varargin{:});

Error in matlab.internal.webwindow (line 163)
obj.impl = obj.createImplementation(varargin{:});

Error in matlab.ui.internal.controller.platformhost.CEFFigurePlatformHost/createView (line 81)
this.CEF = matlab.internal.webwindow(peerModelInfo.URL, peerModelInfo.DebugPort, position);

Error in matlab.ui.internal.controller.FigureController/createView (line 529)
this.PlatformHost.createView(this.PeerModelInfo, pos, title, visible, resizable, windowState, windowStyle, this.Model.Uuid);

Error in matlab.ui.internal.componentframework.WebComponentController/add (line 69)
obj.createView( parentController, parentView, propertiesStruct );

Error in matlab.ui.internal.controller.WebCanvasContainerController/add (line 43)
[e-mail]( this, webComponent, parentController );

Error in matlab.ui.internal.componentframework.WebControllerFactory/create (line 94)
component.createController( parentController, [] );

Error in vmcHub/createProgressBar (line 3212)
drawnow;

Error in vmcHub/createComponents (line 5862)
app.createProgressBar;

Error in vmcHub (line 9278)
createComponents(app)

Error in vmcHubCallback (line 77)
vmcHub(getfullname(blockHdl));]
>> 

Answer 1

[Stefanie Schwarz]

The same question was asked here: Trouble with Vitis Model Composer 2023.2! MATLAB R2021b crashes when I want to open the Model Composer Hub component. - MATLAB Answers - MATLAB Central

It seems that the "Model Composer Hub" block attempts to open a window by using the MATLABWindow feature, which fails.

Test that the MATLABWindow feature is operational for your MATLAB installation by running:

>> cd(matlabroot)
>> cd bin/glnxa64
>> !./MATLABWindow -url=mathworks.com

This code should open a window showing the MathWorks website. If not, see this MATLAB Answer.

If the above commands open a window showing the MathWorks website successfully, then the issue lies with the third-party product "Vitis Model Composer" which is developed by Xilinx/AMD and is external to MathWorks. We recommend contacting Xilinx support for further help.

Below are some solutions that have unblocked other users who encountered the error:

Option 1: Check Model Composer, MATLAB & OS versions

• Ensure that you are using a version of Vitis Model Composer that is supported with your current version of MATLAB.
• Ensure that you are using an exact Linux distribution that is supported by both Vitis Model Composer and MATLAB.
• Use the latest possible version of Vitis Model Composer for your current version of MATLAB.

This MATLAB Answer has more details on Model Composer & MATLAB and OS compatibility:

Which versions of Xilinx System Generator (now AMD Vitis Model Composer) support which MATLAB release?

Option 2: Modify LD_LIBRARY_PATH defined in MATLAB session

One user also reported the following workaround:

When starting MATLAB via Model Composer, the LD_LIBRARY_PATH looks as follows for their R2022b installation:

>> oldpath = getenv("LD_LIBRARY_PATH")
ans =
'/usr/local/MATLAB/R2022b/sys/os/glnxa64:/usr/local/MATLAB/R2022b/bin/glnxa64:/ ... '

After opening the Model Composer Simulink model, the path changes to:

>> newpath = getenv("LD_LIBRARY_PATH")
ans =
'/tools/Xilinx/Vivado/2023.2/lib/lnx64.o:/usr/local/MATLAB/R2022b/sys/os/glnxa64:/ ... '

So Model Composer modifies the LD_LIBRARY_PATH by adding /tools/Xilinx/Vivado/2023.2/lib/lnx64.o with the highest priority (first path). With this configuration, opening the "Vitis Model Composer Hub" block in the model will fail.

After they reverted the LD_LIBRARY_PATH manually with "setenv":

>> setenv("LD_LIBRARY_PATH", oldpath)

then they could open the "Model Composer Hub" window without error.

If this works, you could consider adding the call to "setenv" to either a model callback or block callback, so you don't always have to run it manually:

• https://www.mathworks.com/help/simulink/ug/model-callbacks.html
• https://www.mathworks.com/help/simulink/ug/block-callbacks.html

(which callback may work depends on where Xilinx places the call that modifies LD_LIBRARY_PATH, which we are not aware of).