MATLAB 2015a gives an error when booting, then no graphics functions work

When I boot MATLAB 2015a, I get the following error:

Error in isappdata (line 1)
function result = isappdata(handle, name)

Output argument "result" (and maybe others) not assigned during call to "isappdata".

Error in connector.internal.autostart.run>autoStartEnabled (line 17)

Error in connector.internal.autostart.run (line 6)

To be extra sure, I made sure there isn't some other function or script called "isappdata":

>> which('isappdata', '-all')
C:\Program Files\MATLAB\R2015a\toolbox\matlab\graphics\isappdata.m

Then, I can use many of the built-in MATLAB functions, but anything involving graphics or plotting fail with the error message "Attempt to execute SCRIPT as a function". Normally that error would imply that I have some other script with the same name as the function that I'm using, but I know I don't, and can check by using which().

>> a = linspace(1, 10);
>> plot(a)
Attempt to execute SCRIPT plot as a function:
C:\Program Files\MATLAB\R2015a\toolbox\matlab\graph2d\plot.m

>> which('plot', '-all')
C:\Program Files\MATLAB\R2015a\toolbox\matlab\graph2d\plot.m
C:\Program Files\MATLAB\R2015a\toolbox\matlab\polyfun\@alphaShape\plot.m     % alphaShape method
C:\Program Files\MATLAB\R2015a\toolbox\matlab\timefun\@duration\plot.m       % duration method
C:\Program Files\MATLAB\R2015a\toolbox\matlab\timefun\@datetime\plot.m       % datetime method
C:\Program Files\MATLAB\R2015a\toolbox\matlab\timeseries\@timeseries\plot.m  % timeseries method
>> b = magic(10);
>> imagesc(b);
Attempt to execute SCRIPT image as a function:
C:\Program Files\MATLAB\R2015a\toolbox\matlab\specgraph\image.m

Error in imagesc (line 18)
    hh = image(varargin{1},'CDataMapping','scaled');

>> which('image', '-all')
C:\Program Files\MATLAB\R2015a\toolbox\matlab\specgraph\image.m

I have tried:

1. Restarting MATLAB
2. Restarting my computer
3. Uninstalling MATLAB, deleting the MathWorks folder from C:\Program Files, deleting any MathWorks folders in AppData, restarting my computer, then reinstalling MATLAB

[Image Analyst]

Please attach your startup.m file, or else call the Mathworks since it appears to be an installation issue. http://matlab.wikia.com/wiki/FAQ#After_installation.2C_MATLAB_crashes_or_gives_an_error_message_when_I_try_to_run_MATLAB.

Answer 1

[Andrew Curtis]

I was eventually able to solve this problem by deleting the _temp_matlab_2015a_win64 folder from my Downloads folder and reinstalling.