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

**URL:** <https://forum.plexim.com/t/plecs-blockset-installation-problem-undefined-function-or-variable-plecslib/258>\
**Category:** PLECS\
**Tags:** installation, plecs-blockset\
**Created:** [January 26, 2018, 9:18pm UTC](https://forum.plexim.com/t/plecs-blockset-installation-problem-undefined-function-or-variable-plecslib/258 "2018-01-26T21:18:32Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![royaf](https://avatars.discourse-cdn.com/v4/letter/r/bbce88/32.png) [@royaf](https://forum.plexim.com/u/royaf)\
**Post date:** [January 26, 2018, 9:18pm UTC](https://forum.plexim.com/t/plecs-blockset-installation-problem-undefined-function-or-variable-plecslib/258/1 "2018-01-26T21:18:32Z")

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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?

Regards,

Roy Francis

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**Author:** ![Vitalik\_Ablaev](https://dub1.discourse-cdn.com/flex006/user_avatar/forum.plexim.com/vitalik_ablaev/32/6_2.png) [@Vitalik\_Ablaev](https://forum.plexim.com/u/Vitalik_Ablaev)\
**Post date:** [January 29, 2018, 11:29am UTC](https://forum.plexim.com/t/plecs-blockset-installation-problem-undefined-function-or-variable-plecslib/258/2 "2018-01-29T11:29:42Z")

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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: [http://plexim.com/support/videos/installing-blockset-win](http://plexim.com/support/videos/installing-blockset-win). 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.

Regards,

Vitalik

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**Author:** ![royaf](https://avatars.discourse-cdn.com/v4/letter/r/bbce88/32.png) [@royaf](https://forum.plexim.com/u/royaf)\
**Post date:** [January 29, 2018, 9:40pm UTC](https://forum.plexim.com/t/plecs-blockset-installation-problem-undefined-function-or-variable-plecslib/258/3 "2018-01-29T21:40:24Z")

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Dear Vitalik,

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

Thanks & Regards,

Roy Francis