MATLAB 2014a cannot enable parpool

Hi, I tried to enable parpool in MATLAB 2014a, it gives following message Error using parpool (line 99) The operation must modify one or more Settings files for these levels: factory, user, but you do not have write permission on these levels: user.

Error in parallel.internal.ui.PoolHelper.startPool (line 11) parpool();

I have all permissions, I tried to uninstall and install again, but after one or two days, this problem come out again

[Elwin Chan]

Hi Ming,

Can you tell me:

• what platform you are running on?
• where is the MATLAB installation?
• what is the location of your preferences directory and do you have full read/write access to that location?

You can find the preferences directory using the

 prefdir

command in MATLAB.

If you close MATLAB and then delete parallel.settings file in your preferences directory and try again, does the error still occur?

If that doesn't fix it, then please try the following code in MATLAB:

s = Settings;
s.parallel
s.parallel.addNode('test')
s.parallel.test.addKey('testKey')
s.parallel.test.isSet('testKey')
s.parallel.removeNode('test')

Thanks,

Elwin

[Ming]

Hi, Elwin

I am runing windows 7 sp1 x64 with all patches installed up-to-date. I am runing on my own PC, directly in the Administrator account, I have all permissions to run and change anything. The matlab is installed at C:\Program Files\MATLAB\R2014a I tried your suggestions, but it still doesn't work, unless I reinstall matlab, but 2, 3 days later this problem will appear again.

Someone post exact same problem in April:

http://www.mathworks.co.uk/matlabcentral/answers/125021-parallel-computing-corruption-problem-windows

[Elwin Chan]

Hi Ming,

Thanks for the info. When it is not working, please can you try the following code and reply with the results? (The code won't fix the problem, but might help to diagnose the issue.)

s = Settings;
s.parallel
s.parallel.addNode('test')
s.parallel.test.addKey('testKey')
s.parallel.test.isSet('testKey')
s.parallel.removeNode('test')

Thanks,

Elwin

[Ming]

Hi,

Thank you for your replying, here are the results

    s = Settings;
s.parallel
s.parallel.addNode('test')
s.parallel.test.addKey('testKey')
s.parallel.test.isSet('testKey')
s.parallel.removeNode('test')

ans =

Settings with no properties.

ans =

     0

Answer 1

[Elwin Chan]

I debugged Ming's MATLAB installation, and the problem was that there was a 3rd party MATLAB toolbox installed that contained a file called assert.m which was higher up on the MATLAB search path than the built-in MATLAB function. This was causing MATLAB's built-in assert function to be shadowed, and caused the error.

You can see which assert function will used by calling

 which -all assert

You want built-in (L:\Bparallel\matlab\toolbox\matlab\lang\assert) to be the first one on the list. If it is not the first on on the list, then you should re-arrange your path using MATLAB's path tool.

[Ming]

Thank you again Elwin, the MATLAB is now running fine.

[Sean de Wolski]

I've seen uses' asserts break lots of things; it's probably the most shadowed function I've seen.