Why do I get an error saying "Undefined function or variable 'matlabrc'" when executing a program that uses a MATLAB-compiled shared library?

I am trying to use a MATLAB-compiled shared library in a C++ program. There are no issues when I use the same code with the libraries compiled using MATLAB Compiler 4.7 (R2007b). However, when I recompile all the MATLAB libraries using MATLAB Compiler 4.9 (R2008b) and then try to execute the same program, the <libName>Initialize() function fails with the following error:

??? Undefined function or variable 'matlabrc'

Answer 1

[MathWorks Support Team]

Starting in MATLAB R2008a (or MATLAB Compiler 4.8), CTF data is now automatically embedded directly in the C/C++ binaries (e.g., shared libraries, executables) by default. In order to override this default functionality, you must compile using "mcc" with the "-C" option. This option prevents deployable archives  (e.g., CTF files) from being embedded in binaries.

In the specified error message, the function "matlabrc" is not found. "matlabrc" is usually included in the CTF archive, so you may receive this error if the application is unable to find the CTF archive. When building some applications under certain release build procedures, shared libraries involved in the process may be "stripped"(i.e., trimmed of certain data). If the embedded CTF archives in shared libraries are stripped in this process, the driver application may not be able to find the CTF data during execution.

If your application build process performs such a process, please compile with the "-C" option, which will prevent CTF files from being embedded in binaries.

Another workaround here is to delete the CTF extraction folder, and run the EXE  of your compiled application again. If the "MCR_CACHE_ROOT" environment variable is not set and you are using a Windows machine, the CTF extraction location can be found at the following temporary directory:

C:\Users\[username]\AppData\Local\Temp\[username]\mcrCache[version]

Otherwise, this information will be saved to the location specified by the "MCR_CACHE_ROOT" environment variable. To ensure that Windows does not remove files in this temporary directory, you may set up the "MCR_CACHE_ROOT" environment variable to point to a non-temporary directory you have write access to.

If neither of these workarounds resolve the issue, follow these additional troubleshooting steps, previously found at https://www.mathworks.com/help/compiler/index.html :\n\n

1) Ensure that your application runs in MATLAB (uncompiled) without this error.

2) Ensure that MATLAB starts up without this error.

3) Verify that the generated deployable archive contains a file called matlabrc.m

4) Verify that the generated code (in the "_mcc_component_data.c" file) adds the deployable archive folder containing matlabrc.m to the MATLAB runtime path

5) Delete the "*_mcr" folder and rerun the application.

6) Recompile the application.

 

Answer 2

[Patrick Rollin]

I've had this issue arise from a perfectly working Matlab executable via MCR2013a (v8.1)... and one day it stopped working.

I solved the issue (for Windows 7 64bit) by:

1) deleting the Matlab Runtime Compiler temporary cache folder.

     e.g.(C:\Users\[username]\AppData\Local\Temp\[username]\mcrCache[version])

2) re-ran the executable manually to rebuild the required cache folder.

Every time this issue re-arises I simply repeat these 2 steps and I'm back in business.

Cheers.

[KAE]

This needs to be in the documentation, in a location that users can easily find it. I would have been in real trouble without your answer.

Answer 3

[Image Analyst]

I was told by tech support that if the MCR extracts to

C:\Users\[username]\AppData\Local\Temp\[username]\mcrCache[version]

like it normally does, then because it's in a "Temp" folder, Windows might go in there on occasion and delete files to free up space. If a file had been deleted, this would give rise to the error. If you delete this folder, then when you run your application again, it will see that the temp folder is missing and will recreate it, restoring any missing files, thus letting it work again.

In the future, to avoid having Windows delete any of these files, you can have your deployed application extract the MCR/CTF to a non-temporary folder that you have write permission to. That way, Windows won't touch the files. To do this you need to set a System level environment variable. So bring up the Environment Variable control panel and make a system level variable called MCR_CACHE_ROOT and set it to some folder you have access to, like

MCR_CACHE_ROOT = C:\Users\Public\Documents\MATLAB\MCR

Your apps will extract the CTF to that folder. It seems each app has its own subfolder under that folder.

[Jason]

OK, so I have added all the files first before compiling.

However, on the target computer I am getting an error loading a specific dll (thats on the target PC)

Error while loading PI_GCS2_DLL_x64.dll.

The PI_GCS2_DLL_x64.dll was assumed to have the following path:
C:\ProgramData\PI\GCSTranslator\PI_GCS2_DLL_x64.dll

The PI MATLAB DRIVER GCS2 either could not find or could not use the "PI_GCS2_DLL_x64.dll".
Make sure you have installed the newest driver for your PI controller and look at the PI MATLAB DRIVER GCS2 Manual in chapter "Troubleshooting" headword "PI GCS2 DLL" for known problems and fixes for problems while loading the PI_GCS2_DLL_x64.dll.

Additional Information: MATLAB itself raised the following error:
The specified module could not be found.

But it is there.

[Image Analyst]

Just before you try to call loadlibrary() with that filename, try this:

if ~isfile(fullFileName)
    % File not found.
    errorMessage = sprintf('ERROR : DLL file not found:\n%d', fullFileName);
    fprintf('%s\n', errorMessage);
    uiwait(errordlg(errorMessage));
else
    successMessage = sprintf('SUCCESS!  I found the DLL file at "%s".', fullFileName);
    fprintf('%s\n', successMessage);
    uiwait(helpdlg(successMessage));
end

What does the end user see?