Message appearing on start of the Matlab 2019a

Following message appears on the start of MATLAB

Cannot create file migratePref.txt!

java.io.IOException: The system cannot find the path specified

at java.io.WinNTFileSystem.createFileExclusively(Native Method)

at java.io.File.createNewFile(File.java:1012)

at com.mathworks.services.Prefs.readMigrateFlag(Prefs.java:2153)

at com.mathworks.services.Prefs.createTwoWayMapPrefsSettings(Prefs.java:373)

at com.mathworks.services.Prefs.<clinit>(Prefs.java:214)

at java.lang.Class.forName0(Native Method)

at java.lang.Class.forName(Class.java:264)

at com.mathworks.util.PostVMInit$StartupClass.init(PostVMInit.java:156)

at com.mathworks.util.PostVMInit.perform(PostVMInit.java:187)

On trying to start the simulink following message is coming

simulink

Cannot write to preference file "matlab.prf" in "C:\MATLAB_preferences ".

Check file permissions.

Cannot write to preference file "matlab.prf" in "C:\MATLAB_preferences ".

Check file permissions.

Cannot write to preference file "matlab.prf" in "C:\MATLAB_preferences ".

Check file permissions.

An error was encountered while saving the command history

java.io.FileNotFoundException: C:\MATLAB_preferences \History.xml (The system cannot find the path specified)

at java.io.RandomAccessFile.open0(Native Method)

at java.io.RandomAccessFile.open(RandomAccessFile.java:316)

at java.io.RandomAccessFile.<init>(RandomAccessFile.java:243)

at com.mathworks.mde.cmdhist.AltHistoryCollection$CommandSaver.run(AltHistoryCollection.java:1214)

at java.lang.Thread.run(Thread.java:748)

Please suggest the solution

[Walter Roberson]

https://www.mathworks.com/help/matlab/matlab_env/preferences.html

https://www.mathworks.com/matlabcentral/answers/309984-what-is-the-default-location-of-the-matlab-preferences-directory

https://www.mathworks.com/matlabcentral/answers/93696-how-do-i-change-the-matlab-preferences-directory-location

Check to see whether you have an environment variable named MATLAB_PREFDIR

Answer 1

[Gagandeep Sharma]

I got following kind of message in command window on the launch of MATLAB and simulink

Cannot create file migratePref.txt!

java.io.IOException: The system cannot find the path specified

at java.io.WinNTFileSystem.createFileExclusively(Native Method)

at java.io.File.createNewFile(File.java:1012)

at com.mathworks.services.Prefs.readMigrateFlag(Prefs.java:2153)

at com.mathworks.services.Prefs.createTwoWayMapPrefsSettings(Prefs.java:373)

at com.mathworks.services.Prefs.<clinit>(Prefs.java:214)

at java.lang.Class.forName0(Native Method)

at java.lang.Class.forName(Class.java:264)

at com.mathworks.util.PostVMInit$StartupClass.init(PostVMInit.java:156)

at com.mathworks.util.PostVMInit.perform(PostVMInit.java:187)

Cannot write to preference file "matlab.prf" in "C:\MATLAB_preferences ".

Check file permissions.

Cannot write to preference file "matlab.prf" in "C:\MATLAB_preferences ".

Check file permissions.

Cannot write to preference file "matlab.prf" in "C:\MATLAB_preferences ".

Check file permissions.

The desktop configuration was not saved successfully

Cannot write to preference file "matlab.prf" in "C:\MATLAB_preferences ".

Check file permissions.

>> simulink

An error was encountered while saving the command history

java.io.FileNotFoundException: C:\MATLAB_preferences \History.xml (The system cannot find the path specified)

at java.io.RandomAccessFile.open0(Native Method)

at java.io.RandomAccessFile.open(RandomAccessFile.java:316)

at java.io.RandomAccessFile.<init>(RandomAccessFile.java:243)

at com.mathworks.mde.cmdhist.AltHistoryCollection$CommandSaver.run(AltHistoryCollection.java:1214)

at java.lang.Thread.run(Thread.java:748)

Cannot write to preference file "matlab.prf" in "C:\MATLAB_preferences ".

Check file permissions.

>>

Please advise the step wise solution in detail. that how can I fix the problem. The abovesaid links are not understandable to me.

[Walter Roberson]

At the DOS command prompt give the command

 echo %MATLAB_PREFDIR%

and tell us what it says. Note that this is in Windows, not in MATLAB. If you are already in MATLAB you could try

 !echo %MATLAB_PREFDIR%

Also in MATLAB please show us the output of

 prefdir
 

[Gagandeep Sharma]

The DOS command prompt result is attached as screen shot and MATLAB command window result is as follows:

annot write to preference file "matlab.prf" in "C:\MATLAB_preferences ".

Check file permissions.

Cannot write to preference file "matlab.prf" in "C:\MATLAB_preferences ".

Check file permissions.

The desktop configuration was not saved successfully

Cannot write to preference file "matlab.prf" in "C:\MATLAB_preferences ".

Check file permissions.

>> prefdir

An error was encountered while saving the command history

ans =

'C:\MATLAB_preferences '

java.io.FileNotFoundException: C:\MATLAB_preferences \History.xml (The system cannot find the path specified)

at java.io.RandomAccessFile.open0(Native Method)

at java.io.RandomAccessFile.open(RandomAccessFile.java:316)

at java.io.RandomAccessFile.<init>(RandomAccessFile.java:243)

at com.mathworks.mde.cmdhist.AltHistoryCollection$CommandSaver.run(AltHistoryCollection.java:1214)

at java.lang.Thread.run(Thread.java:748)

Please see

[Walter Roberson]

At the MATLAB command window, please show the output of these two commands:

!echo %MATLAB_PREFDIR%
!echo %USERPROFILE%
!set

The ! are part of the commands.

Answer 2

[Gagandeep Sharma]

Following are the outputs

>> !echo %MATLAB_PREFDIR %

%MATLAB_PREFDIR %

>> !echo %USERPROFILE %

%USERPROFILE %

>> !set

ALLUSERSPROFILE=C:\ProgramData

APPDATA=C:\Users\gaggu\AppData\Roaming

CommonProgramFiles=C:\Program Files\Common Files

CommonProgramFiles(x86)=C:\Program Files (x86)\Common Files

CommonProgramW6432=C:\Program Files\Common Files

COMPUTERNAME=DESKTOP-1VD041H

ComSpec=C:\WINDOWS\system32\cmd.exe

DriverData=C:\Windows\System32\Drivers\DriverData

FPS_BROWSER_APP_PROFILE_STRING=Internet Explorer

FPS_BROWSER_USER_PROFILE_STRING=Default

HOMEDRIVE=C:

HOMEPATH=\Users\gaggu

KMP_BLOCKTIME=1

KMP_HANDLE_SIGNALS=0

KMP_STACKSIZE=512k

LOCALAPPDATA=C:\Users\gaggu\AppData\Local

LOGONSERVER=\\DESKTOP-1VD041H

MATLAB_ARCH=win64

MATLAB_PREFDIR=C:\MATLAB_preferences

NUMBER_OF_PROCESSORS=4

NVIDIAWHITELISTED=0x01

OneDrive=C:\Users\gaggu\OneDrive - uoit.net

OneDriveCommercial=C:\Users\gaggu\OneDrive - uoit.net

OS=Windows_NT

Path=C:\Program Files\MATLAB\R2019a\bin\win64;C:\Program Files (x86)\Common Files\Oracle\Java\javapath;C:\Program Files (x86)\Intel\iCLS Client\;C:\Program Files\Intel\iCLS Client\;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Program Files (x86)\Intel\Intel(R) Management Engine Components\DAL;C:\Program Files\Intel\Intel(R) Management Engine Components\DAL;C:\Program Files (x86)\Intel\Intel(R) Management Engine Components\IPT;C:\Program Files\Intel\Intel(R) Management Engine Components\IPT;C:\Program Files (x86)\NVIDIA Corporation\PhysX\Common;C:\WINDOWS\system32;C:\WINDOWS;C:\WINDOWS\System32\Wbem;C:\WINDOWS\System32\WindowsPowerShell\v1.0\;C:\WINDOWS\System32\OpenSSH\;C:\Program Files\MATLAB\R2019a\bin;C:\Users\gaggu\AppData\Local\Microsoft\WindowsApps;

PATHEXT=.COM;.EXE;.BAT;.CMD;.VBS;.VBE;.JS;.JSE;.WSF;.WSH;.MSC

PROCESSOR_ARCHITECTURE=AMD64

PROCESSOR_IDENTIFIER=Intel64 Family 6 Model 142 Stepping 9, GenuineIntel

PROCESSOR_LEVEL=6

PROCESSOR_REVISION=8e09

ProgramData=C:\ProgramData

ProgramFiles=C:\Program Files

ProgramFiles(x86)=C:\Program Files (x86)

ProgramW6432=C:\Program Files

PROMPT=$P$G

PSModulePath=C:\Program Files\WindowsPowerShell\Modules;C:\WINDOWS\system32\WindowsPowerShell\v1.0\Modules

PUBLIC=C:\Users\Public

QT_QPA_PLATFORM=windows:fontengine=freetype

SESSIONNAME=Console

SHIM_MCCOMPAT=0x800000001

SystemDrive=C:

SystemRoot=C:\WINDOWS

TEMP=C:\Users\gaggu\AppData\Local\Temp

TMP=C:\Users\gaggu\AppData\Local\Temp

USERDOMAIN=DESKTOP-1VD041H

USERDOMAIN_ROAMINGPROFILE=DESKTOP-1VD041H

USERNAME=gaggu

USERPROFILE=C:\Users\gaggu

windir=C:\WINDOWS

__KMP_REGISTERED_LIB_11360=00007FFFD574E2B4-cafed1e7-libiomp5md.dll

[Walter Roberson]

You consistently added a space to the command. I did not say

!echo %MATLAB_PREFDIR %

I said

!echo %MATLAB_PREFDIR%

exclamation-mark e c h o SPACE percent M A T L A B underscore P R E F D I R percent

not

exclamation-mark e c h o SPACE percent M A T L A B underscore P R E F D I R SPACE percent

Anyhow, the result of !set shows:

MATLAB_PREFDIR=C:\MATLAB_preferences

which is what we needed to know.

You should follow the directions at https://www.architectryan.com/2018/08/31/how-to-change-environment-variables-on-windows-10/ and DELETE the environment variable named MATLAB_PREFDIR

Note: if you are working on a corporate system, or working on a system set up by a university IT team, then you might possibly not have administrator access to change this variable, or the variable might be set by GROUP Policy. If so you might need to get the IT people to change the variable.

If changing the variable is not possible for some reason, then at the very least, someone with admin access should create the directory C:\MATLAB_preferences and give you write access.

If changing the variable is not possible, and creating that directory is not possible, then you should consider creating a .bat file that does

SET MATLAB_PREFDIR=

and then starts MATLAB.

[Gagandeep Sharma]

I did not added any space to the command. I only copy paste the command on MATLAB command window. I tried again by deleting the space, again after copying and pasting as follows:

>> !echo%MATLAB_PREFDIR%

The filename, directory name, or volume label syntax is incorrect.

>> !echo %MATLAB_PREFDIR%

C:\MATLAB_preferences

>>

I will now do the other task which you suggested.

Thanks