This error indicates that you have installed the Parallel Computing Toolbox, but have not installed the MATLAB Parallel Server. MATLAB Parallel Server products use a separate license and installation key.
To resolve this error, install the MATLAB Parallel Server, then run "mjs install" or "mjs start" again.
If you have MATLAB Parallel Server installed and are still receiving this error, it may be caused by a missing "mjsd.exe" file. This file is located in the $MATLAB\toolbox\parallel\bin\$ARCH directory (where $MATLAB is the MATLAB installation directory, and $ARCH is the directory specific to the architecture of your system - e.g. win32, win64, gnlx86, glnxa64). If this file does not exist, reinstall MATLAB Parallel Server.
If mjsd.exe exists, but you still receive the error, mjs.bat may be looking for the file in the wrong location. Open the file $MATLAB\toolbox\parallel\bin\util\setbase.bat. Go to the line where BINBASE is set:
Change %ARCH% to the correct architecture of your MATLAB Parallel Server installation (e.g. win32, win64, glnx86, glnxa64). For example, if you are on a 64-bit Windows system with a 64-bit MATLAB Parallel Server installation, the line should be:
After making this change and saving the file, run "mjs install" again. If you still receive the same error message, open the file $MATLAB\toolbox\parallel\bin\mjs.bat. Edit the line that calls mjsd.exe:
Replace %BINBASE%\mjsd.exe with the local path to mjsed.exe. For example, if you have a 64-bit installation of MATLAB Parallel Server installed in C:\Program Files\MATLAB\R2019b, the line would be:
call "C:\Program Files\MATLAB\R2019b\toolbox\parallel\bin\win64\mjsd.exe"
Save the mjs.bat file and run "mjs install".
NOTE: Starting in R2019b the following name changes occurred: * MATLAB Distributed Computing Server was renamed to MATLAB Parallel Server * mdce_def was renamed to mjs_def * mdce binary was renamed to mjs * mjs scripts are in $MATLAB/R20XXx/toolbox/distcomp/bin for R2019a and earlier