Why do I receive warning messages about the Toolbox Path Cache when starting MATLAB?

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I receive some or all of the following warning messages when starting MATLAB:
\\System\MATLAB\toolbox\toolboxname not found in Toolbox Path Cache
Warning: MATLAB Toolbox Path Cache is out of date and is not being used.
Warning: Unable to load Toolbox Path Cache
I would like to know what these messages mean. I wonder if there is something wrong with the Toolbox Path Cache, and if MATLAB will still function properly.

Accepted Answer

MathWorks Support Team
MathWorks Support Team on 22 Oct 2021
Edited: MathWorks Support Team on 26 Oct 2021
The Toolbox Path Cache is a file that MATLAB uses to store information regarding the location of toolbox directories. It is used because loading the information from a single local file is quicker than accessing the file system, particularly when there are many toolboxes or the directories are being accessed across a network. The cache file will also be updated at the end of each MATLAB session. More information regarding the toolbox path cache is available here:
Both error messages indicate that there is an issue with the current Toolbox Path Cache file. Generally both errors will be resolve by restarting MATLAB as it will generate a new Toolbox Path Cache. If the error does return there are two ways to reset the Toolbox Path Cache
1. Using the command:
>> rehash toolboxcache
2. From the MATLAB Desktop:
Open the Preferences GUI. For MATLAB 7.14 (R2012a) and earlier releases go to the File menu to Preferences. For MATLAB 7.14 (R2012b) and later releases go to the Home tab to Preferences. In the Preferences GUI, select the "General" tab. Click the "Update Toolbox Path Cache" button to reset the Toolbox Path Cache.
After the Toolbox Path Cache is reset, the error should not return on startup.
  3 Comments
Johannes Kalliauer
Johannes Kalliauer on 11 Dec 2018
Thanks @MathWorksSupportTeam!
I had a similar issue:
Warning: Unable to load Toolbox Path Cache/home/lv71022/jkalliau/.matlab/R2018b/toolbox_cache-9.5.0-647392850-glnxa64.xml.The cache file is not in the correct format. It will be regenerated upon quitting MATLAB.
But it did not regenerate upon quitting. I run matlab -r "rehash toolboxcache" and now everything works. :-D

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More Answers (3)

cui
cui on 29 May 2019
it works! thanks

Yvan N.
Yvan N. on 30 May 2019
You can just quot matlab, then delete the problematıc toolbox fıle, after that open matlab agaın

Sindhu M
Sindhu M on 17 Jul 2021
Matlab toolbox path cache is out of date and is not being used.

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