MATLAB no longer able to save files

I'm trying to save a matlab file I'm working on, but whenever I click save, it gives me this error and is unable to save the file:

This is on a new script. When I try and save changes to an old file, it gives me this error:

I've had MATLAB on my computer for a few months and haven't had any similar problems until today. I have tried restarting MATLAB, restarting my computer, uninstalling and reinstalling MATLAB, and running MATLAB as an administrator. I am able to save in C:\Users\username, but not in C:\Users\username\Documents. The error occurs even in new files with just a test comment.

Answer 1

[Jan]

Your virus scanner can block the access to the Documents folder to impede crypto locker, e.g. BitDefender does this. So check if Matlab is a trusted application in the preferences of your anti virus software.

Do you have access to the folder in the Windows Explorer? Can you create files and folders inside it? If not, maybe you have changed the privileges for this folder by accident. Check the permissions of the folder.

[Andrew Agner]

I was able to solve the problem. It was the controlled folder setting in Windows Defender. Thanks for the help!

Answer 2

[Boris Venet]

This issue has arisen yet again, at least on my machine, immediately after the most recent Windows 10 update. This is the update named "Oct 2018", although it was only pushed to me a couple of days ago. I'm running Matlab 2016A. I experienced the following symptoms:

(1) In the Matlab editor, when I press menu items "Save - SaveAs", nothing happens (no directory window open up). I.e., I was unable to save new m-files from the editor.

(2) When I press menu item "Open", I do get the list of recently-opened files plus the general "Open ..." option. However, if I select "Open ...", again nothing happens (no directory window opens up). On the other hand, I CAN open existing m-files from the previous-file list, OR by clicking on them in File Explorer. Also, I can edit and resave the OLD files from the Matlab editor, once they've been opened as just described. BUT the key issue is that no new files can be saved from the editor.

The only solution I've found is to roll back the offending Windows update. This requires the Windows procedure "Start - Settings - Security and Updates - Recovery - Go back to an earlier build ...".

(Prior to rolling back to the previous Windows version, I checked various things suggested by other Matlab and Windows users with similar problems. This included checking folder permissions, current user being administrator, turning off the "Protected folders" option in the Oct 2018 security update; none of these suggestions worked. The only thing that worked for my case was rolling back the Oct 2018 Windows update.)

[Jan]

This is the typical horror of Windows Updates. Please publish this in a new thread, because it is not an answer of the original question, which was related to the folder protection. Your problem is different, but such important, that it is worth to be published individually, instead of beeing hidden as a not really matching comment. Thanks.