This inconsistency can be caused by any previous Support Package installation performed on the machine. Support packages can not currently be installed on multiple accounts. To avoid it, you can follow the steps below:
1. Delete the contents of the "SupportPackages" folder (not the folder itself) located inside the MATLAB folder.
Windows: C:\MATLAB\SupportPackages Mac\Linux: Documents\MATLAB\SupportPackages
2. Update the toolbox list to reflect the changes by executing the following command:
>> rehash toolboxcache
3. Reset the MATLAB search path to default by running the following commands:
>> restoredefaultpath >> savepath
4. Install the support packages.
Note that this solution will remove any partial or complete support package installations for other users as well. Currently, support packages are not designed to work with multi-user profile machines and as such, other users will not automatically see them.
As a workaround, you can copy the preferences folder of the user who originally installed the support sackage(s) and replicate it for other users. Replace the existing preferences folder for other users with the preferences folder of the original user. MATLAB stores its preferences under the user profile in:
Windows: C:\Users\<username>\AppData\Roaming\MathWorks\MATLAB\R2015a\ Max\Linux: ~/.matlab/R2015a/
The preferences folder is named the release name for the application. For instance, the preferences for R2014a would be in the specified location in a folder called R2014a.
This workaround would make it so that your instance of MATLAB will be able to see the Support Package that someone else installed on the computer.
Once a support package has been installed, you can use the follow command to verify that the installation was successful.