Trouble Saving Data Structure

I am processing fluorescence data and saving data structures with subject IDs and other relevant trial identifiers as well as several long vectors of signal and time data. I have saved many versions of these structures without ever having encountered a problem. Today, while trying to save another structure, I keep getting errors that say matlab is "unable to write file 'C:\Users ..." and then messages will pop up in the command line saying "An error was encountered while saving the command history" and "The desktop configuration was not saved successfully". I have saved many of these types of structures before, and never had an issue. As far as I know, there is nothing unique to this specific structure that would be causing the problem, and I have since tested it with structures I have saved successfully in the past and gotten the same error. Does anyone know what I can do to successfully save my data?

[Steven Lord]

That's not the full and exact text of the error and/or warning messages you're receiving. Please show us all the text displayed in red in the Command Window (and if there are any warning messages displayed in orange, please show us those too.) The exact text may be useful and/or necessary to determine what's going on and how to avoid the warning and/or error.

[Will]

The full red text is as follows: "Error using save

Unable to write file 'C:\Users\dunnewa\Documents\MATLAB\Experimental Data\aa.mat'."

The other two messages are sometimes (in some errors, not all of them) displayed in black text underneath the error

[Steven Lord]

Okay. Is there already a file in that specific location? If so, please specify that full path to the file in a call to the fileattrib function with two outputs, as I've done below for one of the MATLAB function files included in MATLAB.

b = fullfile(matlabroot, 'toolbox', 'matlab', 'funfun','ode45.m')

b = '/MATLAB/toolbox/matlab/funfun/ode45.m'

[~,values] = fileattrib(b)

values = struct with fields:
            Name: '/MATLAB/toolbox/matlab/funfun/ode45.m'
         archive: NaN
          system: NaN
          hidden: NaN
       directory: 0
        UserRead: 1
       UserWrite: 0
     UserExecute: 0
       GroupRead: 1
      GroupWrite: 0
    GroupExecute: 0
       OtherRead: 1
      OtherWrite: 0
    OtherExecute: 0

Looking at this output, if I were to try to write to the ode45.m file it ought to fail, as the values struct shows that no one should have permissions to Write to that file. I want to see if your file is read-only as well.

If the file doesn't exist, call fileattrib on the directory in which you're trying to save the file, again to see if that directory is read-only.