Parallel processing toobox not working on Ubuntu 18.04

I have installed Matlab R2018a on a fresh install of Ubuntu 18.04. I can't get the parallel processing toolbox to work.

It seems to be correctly installed:

But when I try to open the parallel pool, I get "undefined function or variable":

And if I open the parallel processing "Manage Clusters" box, The dialog gets stuck on "Loading Profiles...":

All other toolboxes are working fine. `Parfor` loops run through in series, as if they were a normal `for` loop.

Any ideas what the problem is?

Thanks

[Adam]

Do you have an active license for the toolbox?

Typing

license( 'test', 'Distrib_Computing_Toolbox' )

should return 1 if you do have an active license.

[Ming Yue]

As Adam mentioned, if you installed parallel computing toolbox but do not have the license, the "parfor" loop till not execute since "parfor" checks for license before invoking workers.

[Sanjay Manohar]

Thanks - it is licensed:

license('test','Distrib_Computing_Toolbox')
ans = 
     1

[Sanjay Manohar]

Update: the toolbox is not listed under 'ver'! Why could this be?

>> ver
-----------------------------------------------------------------------------------------------------
MATLAB Version: 9.4.0.813654 (R2018a)
MATLAB License Number: 972477
Operating System: Linux 4.15.0-33-generic #36-Ubuntu SMP Wed Aug 15 16:00:05 UTC 2018 x86_64
Java Version: Java 1.8.0_144-b01 with Oracle Corporation Java HotSpot(TM) 64-Bit Server VM mixed mode
-----------------------------------------------------------------------------------------------------
MATLAB                                                Version 9.4         (R2018a)
Image Processing Toolbox                              Version 10.2        (R2018a)
Signal Processing Toolbox                             Version 8.0         (R2018a)
Statistics and Machine Learning Toolbox               Version 11.3        (R2018a)

[Walter Roberson]

There are other toolboxes listed in your add-on explorer that also do not show up in ver.

Try

restoredefaultpath
rehash toolboxcache

[Ming Yue]

Also, it's possible that the parallel computing toolbox is not installed correctly.

Can you please try to uninstall that toolbox (in Add-Ons->Manage Add-Ons-> Search for Parallel Computing Toolbox), then install that toolbox again (in Add-Ons->Get Add-Ons-> Search for Parallel Computing Toolbox)?

Answer 1

[Sanjay Manohar]

Thanks all, the commands

restoredefaultpath
rehash toolboxcache

solved the problem.