Startup path issue creating variable errors

I just deleted and installed a clean version of Matlab R2019b, because i was getting the error

Warning: Executing startup failed in matlabrc.
This indicates a potentially serious problem in your MATLAB setup, which should
be resolved as soon as possible.  Error detected was:
MATLAB:load:couldNotReadFile
Unable to read file 'matlab.mat'. No such file or directory. 

My startup.m was just 'load matlab.mat', so I saved the workspace as matlab.mat, and was able to run the application, but not add certain specific paths in that I wanted without getting a persistent popup saying "Variables - an unexpected error has occurred"

I tried restoredefaultpath and rehash toolboxcache, as well as restoredefaultpath;matlabrc .

Now, on the clean install, matlab can't find startup.m.

>> which startup.m
'startup.m' not found.

How is it possible that I don't have a startup.m file on a clean install? Please let me know if you have any thoughts, thanks in advance

Answer 1

[Stephen23]

"How is it possible that I don't have a startup.m file on a clean install"

Because it is a clean install: MATLAB does not create this file, it is created by the user:

https://www.mathworks.com/help/matlab/ref/startup.html

"Please let me know if you have any thoughts"

The documentation states "Create a startup.m file in the userpath folder, which is on the MATLAB® search path. Add commands you want executed at startup....", so that is probably what I would do, e.g. create a script with that name and save it in your startup folder:

https://www.mathworks.com/help/matlab/matlab_env/matlab-startup-folder.html