Why "Unable to parse command history line" error?

Starting today, I get "Unable to parse command history line:" whenever I start Matlab. No other information is provided. I am running 2014a on a Windows 7 machine.

What does this error mean? How do I eliminate whatever problem it's flagging?

Answer 1

[Umakant]

Did you upgrade to MATLAB 8.2(R2014a)?. In this case the Preference Directory might not be managed properly during the upgrade process.

Try regenerating the MATLAB's Preference Directory by following the steps below:

1. Start MATLAB and type the following at the MATLAB command prompt:

>> prefdir

In MATLAB 8.2 (R2014a), the output should look like:

C:\Users\{username}\AppData\Roaming\MathWorks\MATLAB\R2014a (on Windows)

/home/{username}/.matlab/R2014a (on UNIX)

/Users/{username}/.matlab/R2014a (on Mac)

This is where your "matlab.prf" file is located. Your path may be different depending on how your system is setup. The preference directory may be hidden in some operating systems.

2. Make sure that MATLAB is closed and rename the preferences directory of your current MATLAB version and all older versions of MATLAB to something else. For example, in MATLAB 8.2 (R2014a) rename the directory R2014a to R2014a_old.

3. Restart MATLAB. A new preferences directory will be created for the MATLAB version that is launched.

If this does not address the issue, it is possible to restore your preferences by deleting the newly created directories and renaming the R2014a_old to the original names (R2014a).

[K E]

Thanks, this worked and it's helpful to know it might be left over from upgrading to a new version.

[Gabriel Ruiz-Martinez]

Thanks you Umakant, I did your suggestions and really, works. I had the same problem that K E.

Answer 2

[Adam]

You do not really need to delete the entire preferences directory and give up all of your settings. If you prefer keeping your existing MATLAB preferences, simply rename the History.xml to something like History.bak. This should address the issue immediately. Or you can delete this file all together if you do not care about the Command History.

[K E]

Hey, that's great, thanks.