Error with Matlab internal editor

version '9.3.0.713579 (R2017b)'

When I type: syms x y z at command line it works fine. However, if I put it in the editor and then run section, I get the following error:

Error using matlab.internal.editor.eval.FileInfo
Java exception occurred:
java.io.IOException: java.lang.RuntimeException:
Internal Exception in reading MLX file :
fl:filesystem:AccessDenied

  at
    com.mathworks.services.mlx.MlxFileUtils.writeCode(MlxFileUtils.java:204)

Caused by: java.lang.RuntimeException: Internal
Exception in reading MLX file :
fl:filesystem:AccessDenied

  at
    com.mathworks.services.mlx.MlxFileUtils.nativeWriteMlxFile(Native
    Method)

  at
    com.mathworks.services.mlx.MlxFileUtils.writeCode(MlxFileUtils.java:202)

Error in matlab.internal.editor.eval.TmpFilePath.get

Error in matlab.internal.editor.evaluateCode

Error in matlab.internal.editor.evaluateCode

[As Gr]

Hi Chet,

I have occasionally had the same issue with MATLAB, lately. I am using version R2017b, also, and have found that I tend to have this error appear when I run a command in MATLAB after my computer has been locked and in sleep mode for any period of time (with MATLAB open on the computer). I found a similar question asked on MATLAB Answers at the following address: https://au.mathworks.com/matlabcentral/answers/392291-java-error-when-running-script

However, in that case, the issue seemed to be related to running a file on multiple devices at once and/or using multiple versions of MATLAB. I have only ever used version R2017b and only on one device, so I don't believe that this solution would stop me from receiving the error. I suspect it may be related to the computer going to sleep with MATLAB open, although I'm not sure why that would cause an error. Was your device asleep before you started receiving that error?

[Walter Roberson]

Are you using Windows 10? If so then you should upgrade your MATLAB; see https://www.mathworks.com/matlabcentral/answers/399991-syms-sym-and-mupad-functions-cause-matlab-to-freeze

Answer 1

[Marwan Muhammad]

I had the same issue when i tried to run a cell (ctrl+enter) & the reason was that there were 2 open instances of matlab. so, i just had to close one of them.