MATLAB:fullfile, Error in fullfile>locHandleError

The code was working a day before with no problem but today the following error appears

Error using message/getString
Unable to find message key 'UnknownError' in catalog 'MATLAB:fullfile'.

Error in fullfile>locHandleError (line 141)
excToThrow = MException(msgToThrow.Identifier, msgToThrow.getString);

Error in fullfile (line 93)
    locHandleError(exc, varargin);

Error in toolboxdir (line 37)
    s = fullfile(tbxprefix, tbxdirname);

Error in matlab.ui.internal.dialog.DialogUtils.imreadDefaultIcon (line 38)
            iconFileName = fullfile(toolboxdir('matlab'), 'uitools', 'private', ['icon_' iconName '_32.png']);

Error in msgbox>setupStandardIcon (line 446)
[iconData, alphaData] = matlab.ui.internal.dialog.DialogUtils.imreadDefaultIcon(iconName);

Error in msgbox (line 361)
        Img = setupStandardIcon(IconAxes, IconString);

Error in errordlg (line 59)
handle = msgbox(ErrorStringCell,dlgName,'error',replace);

Error in uiopen (line 202)
    errordlg(err);

Answer 1

[Maryam Hasannasab]

Hi Walter, thanks for your patience. I found out where the problem was! Through a power cut or something, I had managed to save 'fullfile.m' into the current folder without I even notice. So MATLAB confused its own fullfile with the one I had saved in the folder. I removed the file so there is no problem any more.

Answer 2

[Walter Roberson]

When you see something about being unable to find the message key, then one of two things has happened:

1. corrupted MATLAB installation; or
2. you have too many files open already and MATLAB is not able to open a file it would use to create the correct error message.

In practice the second of those is much more likely. Try

fopen('all')

to see the list of open files.

[Maryam Hasannasab]

Thank you, Walter for your prompt answer. I tried fopen('all') and I got '[]'. So I uninstalled MATLAB, restarted my PC, installed it again and restarted my PC. Now I can open the files but I receive same errors. Worth to mention that I can even run the codes and get the results but I still have the red lines error with each try.

[Walter Roberson]

What do you see if you

ls(fullfile(toolboxdir('matlab'), 'uitools', 'private', 'icon_error_32.png'))

[Maryam Hasannasab]

This is what I get:

Error using message/getString Unable to find message key 'UnknownError' in catalog 'MATLAB:fullfile'.

Error in fullfile>locHandleError (line 141) excToThrow = MException(msgToThrow.Identifier, msgToThrow.getString);

Error in fullfile (line 93) locHandleError(exc, varargin);

[Walter Roberson]

Does that happen even if the ls() is the first thing you do after restarting MATLAB ?

[Maryam Hasannasab]

No, it doesn't.