Calling MEX function works only after Explorer restart

Hello everyone,

I came across a strange behavior while trying to call a mex function. Basically on the first run, the Matlab crashes, with Access Violation, then after a Windows Explorer restart, the issue is gone.

I'm using the Matlab's simple code for testing purposes.

timestwo2.c

Before Explorer restart:

After a laptop restart, start Matlab (from the Window's Start menu):

Matlab crashes with Access Violation (sample from the log with config info:

--------------------------------------------------------------------------------

Access violation detected at 2024-01-24 14:47:17 +0100

--------------------------------------------------------------------------------

Configuration:

Crash Decoding : Disabled - No sandbox or build area path

Crash Mode : continue (default)

Default Encoding : UTF-8

Deployed : false

Graphics Driver : Uninitialized hardware

Graphics card 1 : Intel Corporation ( 0x8086 ) Intel(R) Iris(R) Xe Graphics Version 31.0.101.4575 (2023-7-11)

Graphics card 2 : NVIDIA ( 0x10de ) NVIDIA GeForce MX550 Version 31.0.15.1789 (2022-12-15)

Java Version : Java 1.8.0_202-b08 with Oracle Corporation Java HotSpot(TM) 64-Bit Server VM mixed mode

MATLAB Architecture : win64

MATLAB Entitlement ID : 10315996

MATLAB Root : C:\Program Files\MATLAB\R2023a

MATLAB Version : 9.14.0.2337262 (R2023a) Update 5

OpenGL : hardware

Operating System : Microsoft Windows 10 Enterprise

Process ID : 3356

Processor ID : x86 Family 6 Model 154 Stepping 4, GenuineIntel

Session Key : 6ded6121-afb7-4385-bdf4-3b430c04d44a

Window System : Version 10.0 (Build 19044)

Restart Windows Explorer via the Windows' Task Manager.

After Explorer restart

Open Matlab via the Windows' Start Menu.

other:

• behavior is similar with different Matlab 2023 versions
• behavior is similar with different mingw versions (6.3 and 8.1)
• environment variables are identical before and after the explorer restart (calling a "set" in command prompt)

Any idea, where the problem might be?

[James Tursa]

How are you calling it?

[Jaroslav]

I am starting the Matlab from the Start menu and the Windows Explorer is restarted via the Task Manager.

[James Tursa]

I mean, how are you calling the timestwo function? Can you give an example?

[Jaroslav]

I might not understand what you mean, the command is in the screenshot above:

mex -g timestwo2.c

[Stefan]

H Jaroslav,

thanks for your request - I have opened a Tech Support Case for you. We will be in touch shortly.

Best,

Stefan