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PLECS Blockset installation problem - undefined function or variable 'plecslib'

+1 vote

Dear Sir,

I have installed PLECS Blockset in the PC with Windows10 Operating system. I have used the trial license.lic file when license file was asked during installation. After installing, I have started MATLAB 2015a and typed plecslib in the command window of MATLAB. 

The following error message came: Undefined function or variable 'plecslib'. 

The MATLAB library does not contain any Plecs blocks in it.

How to solve this license issue?



Roy Francis


asked Jan 27, 2018 by royaf (26 points)

1 Answer

+2 votes
Best answer
Hi Roy,

This error typically occurs if your MATLAB paths weren't properly set. When you installed PLECS Blockset, the installation wizard had you create a startup.m file (at 3:03 of the below video). This file is made to be initialized every time you boot MATLAB and, thus, let your MATLAB add the necessary PLECS and PLECS/demos folders to its path for you automatically. This will only happen, however, if the location of this startup.m file (the default is [your username]/Documents/MATLAB/) is also listed in your MATLAB path. Please verify that all three of these paths highlighted in this installation video are present in your "Set Path" window within MATLAB: If your startup.m file was properly created and pointed to within MATLAB paths, you should get the PLECS and PLECS/demos paths added automatically upon MATLAB reboot. If you need to start the PLECS installation wizard manually for any reason, you may do so via a shortcut in the "PLECS Blockset" folder.


answered Jan 29, 2018 by Vitalik Ablaev (28 points)
selected Jan 30, 2018 by royaf
Dear Vitalik,

Thanks for the reply. The MATLAB Path now corrected and the problem solved.

Thanks & Regards,

Roy Francis