Problems with savepath in R2023b

I have just installed R2023b on two different machines. Both give the following problem, when trying to use savepath

>> addpath(pwd)

>> savepath

Warning: Unable to save path to file 'C:\Program Files\MATLAB\R2023b\toolbox\local\pathdef.m'. You can save your path to a different location

by calling SAVEPATH with an input argument that specifies the full path. For MATLAB to use that path in future sessions, save the path to

'pathdef.m' in your MATLAB startup folder.

> In savepath (line 238)

Any idea why this warning is issued and how to fix it?

[Nick]

The problem is new with R2023b, on the previous versions there were no warnings like that.

[Peter Nelson]

I am seeing the same issue

Answer 1

[Matt J]

Tech Support advised running Matlab "As Administrator" and this did solve the problem.

[Bruno Luong]

This is odd work around, it seems to me MATLAB should be run without administrator right, for whatever reason I can't remember right now (possibly the very reason that you ask here).

EDIT: I just check the doc and it is indeed say

"On a Windows® system with User Account Control (UAC) enabled, you might be prompted to allow the update operation because it requires administrator-level permission."

[Xiaorui Tang]

Thank you for bringing this issue to our attention.

We have confirmed that this is a bug in the savepath function on Windows in MATLAB R2023b, and we sincerely apologize for any inconvenience this may have caused.

We're working on a solution for this issue, which will be included in one of the upcoming MATLAB 2023b Update releases soon.

In the meantime, there are two workarounds to save the path:

1. Manually change the permissions of the pathdef.m file in Windows:

• Use the "which pathdef" command in MATLAB to identify the location of the pathdef.m file. It should be located at <matlabroot>\toolbox\local\pathdef.m
• Navigate to this location in your Windows File Explorer.
• Right-click on the pathdef.m file and select 'Properties'.
• Navigate to the 'Security' tab.
• Click on 'Edit' to change permissions, and ensure 'Full control' is checked under the 'Allow' column for your user account.

OR

2. Run MATLAB with administrative rights:

• Close MATLAB if it is currently open.
• Right-click on your MATLAB shortcut on the desktop or in the start menu.
• Select 'Run as administrator'.

These are temporary workarounds and should be unnecessary once the bug is fixed in the upcoming MATLAB 2023b Update releases.

We appreciate your understanding as we work to resolve this issue.

Thanks,

MathWorks Dev Team

Answer 2

[Walter Roberson]

On a shared system, users should not have write access to pathdef.m inside the MATLAB installation directory.

If this is not a share system, you could try using File Explorer to set you as having write permission to the file. But it being Windows, I do not know if UAC would override that write access since it is a file living inside c:\Program Files . Easiest is to savepath to your userpath . Or change your preferences to point to a different folder; see https://www.mathworks.com/help/matlab/matlab_env/matlab-startup-folder.html

[Rolfe Power]

I don't think this is the issue here. There are valid reasons for setting the pathdef for all users and this worked in previous versions given the user attempting to set the path had admin privileges. Now, it prompts for these privileges then throws the warning seen above even when the change is approved.

Answer 3

[Bruno Luong]

On Windows to fix it you need to change the Security setup of the file pathdef.m Right Click on file, Properties, Tab Security, Select Users, then click on Edit, Check Full Control, Then Apply.

Before

After