Strange warning how to interpret it?

I get this strange warning in command window when MATLAB starts (R2023b)

"[WARN] StAXDialectDetector - Unable to determine dialect of the StAX implementation at jar:file:/C:/Program%20Files/MATLAB/R2023b/java/jarext/axis2/woodstox-core-asl.jar"

Does not occur everytime.

[Neil Palumbo]

I see the same startup error in v2023b.

[WARN] StAXDialectDetector - Unable to determine dialect of the StAX implementation at jar:file:/C:/Program%20Files/MATLAB/R2023b/java/jarext/axis2/woodstox-core-asl.jar!/

[Melih]

I also have the same [WARN] StAXDialectDetector - Unable to determine dialect of the StAX implementation at ... (some local path)

[David]

Same error message on the new R2023b for me too

[Masatoshi Yoshida]

The same warning at the startup of the new R2023b for Apple sillicon mac (macOS Monterey).

[Jorge]

+1

[Michael Vinskus]

I just had the same happen on a clean install of 2023b Update 6 (23.2.0.2365128 (R2023b)) when starting via the desktop shortcut created during installation. The issue does not happen if the program is started:

• Via the Start menu
• By running the executable out of the bin/win64 directory
• From a shortcut which starts from the $matlabroot/bin/win64 directory.

The only difference in the shortcuts is that the one created on install has the "Start in" directory blank.

Answer 1

[Bruno Luong]

Fixed with update 4

https://www.mathworks.com/support/bugreports/3114312

Answer 2

[Nick Patterson]

I got the same warning on my Windows machine when I installed R2023b. I restarted MATLAB and got the exact same error. Reading the comments (since I also had the pre-release for R2023b), I entered this command to clear all my preferences,

cellfun(@rmpref, fieldnames(getpref))

And the error did not occur on two consecutive start ups. I then ran several of my GUI's (which stores preferences), restarted MATLAB, and no more warnings.

So, not sure if this will work for others, but this was my experience:

• Got warning every time I started R2023b (two times on two restarts)
• Removed all preferences, never saw warning again (5 times and counting)

[Bruno Luong]

I suspect that the problem occurs when MATLAB starts and try to read some xml files, perhaps user preference that is saved in xml file.

The fact that you don't see the warning does mean the problem is not there and can cause other issue later.

[J. Alex Lee]

i ran getpref and see export_fig... anyone else with the error use export_fit from FEX or not use it?

[Bruno Luong]

@J. Alex Lee I do not use exportfig.

[IYelin]

@Nick Patterson

I also got the same warning (new installation of MATLAB 2023b on Windows).

I tried to use your solution. However, when I run:

cellfun(@rmpref, fieldnames(getpref))

I get:

Error using fieldnames
Invalid input argument of type 'double'. Input must be a structure or a Java or COM object.

running 'getpref' returns empty, which explains it.

I then edited the preferences which were initially just the default. Specifically, I changed Text display 'line spacing' to 'compact' instead of 'loose'.

restarted matlab and did not get the warning. Hope it keeps this way.

Thanks!

Answer 3

[Walter Roberson]

I got the same thing the first time I started r2023b official on my macos ventura intel (I had prerelease before that.) I created a case about it; Mathworks suggested reinstall, which I have not done. I have not seen it in any of my starts of matlab since the first.

I had speculated that it might have to do with creation of prefdir which would only happen first time. I moved prefdir out of the way but the problem did not occur on start.

I speculated that the prefdir for the prerelease might have conflicted with the official, but I have not restored the old version from backup to test.

If I recall correctly, Bruno, you are using Windows, but I do not recall whether you are using intel or AMD? If you are using Windows then we could rule out it being Mac or Windows specific. (Ah, the file name gives away your os but not your CPU manufacturer)

[Bruno Luong]

Thanks Walter. I use Intel and Windows.

It happens again today. I have restared MATLAB and this warning goes away.

[J. Alex Lee]

I also use Intel and Windows, and see this warning on start-up about every other time I start it up.

I haven't fully established the pattern, but maybe it only happens on a matlab startup after a computer restart.

*update: restarted computer and no warning on first matlab start up (or 2nd or third); sunk my hypothesis

[John]

I am getting the warning in Ubuntu 20.04 too

[Walter Roberson]

Mathworks informs me that they have located the cause of the error and are working on fixing it.

[Hyoki Lee]

@Walter Roberson Thanks. It helps me so I don't need to contact them. :)

[Jon]

I am having the same issue occurring intermittently on my Windows 10 machine.

[WARN] StAXDialectDetector - Unable to determine dialect of the StAX implementation at jar:file:/C:/Program%20Files/MATLAB/R2023b/java/jarext/axis2/woodstox-core-asl.jar!/

@Walter Roberson Good to hear the Mathworks is working on a fix. I will ignore the problem for now and hope that a patch comes soon.

[Bruno Luong]

The R2023b update1 is released yesterday. I didn't check the release note, but the fix could be there.

[Walter Roberson]

The only thing it appears to contain is a fix for

3073147: Incorrect Code Generation: Using a For Each Subsystem block in AUTOSAR might generate incorrect code when allowed stack size is limited

[Jon]

I just installed R2023 Update 1, I still get the StAXDialectDetector error on startup

[Bruno Luong]

@Jon, thanks. Too bad.

Answer 4

[Nathan Kimmitt]

I'm also getting this error, and usually it's followed by the program freezing in the initialization state. I uninstall and reinstall and it fixes the issue but only temporarily. Any ideas? I just tried Nick's suggestion by running:

cellfun(@rmpref, fieldnames(getpref))

so we'll see if that works.

[Bruno Luong]

Have you tried R2023B Update1?

I installed on 2 computers and use them almost 2 days, ni sign of this error (yet?)

[Brian LaRocca]

I just noticed this too. Running 2023b. Never saw with 2022b.

[Brian LaRocca]

Running Windows 11.

[Brian LaRocca]

Ran 2023b Update 1 for Windows. Warning has dissapeared on 1st restart of MATLAB. Thanks Bruno!!

[Cleiton Moya de Almeida]

I'm running 2023b Update 1 and this warning sometimes appears when Matlab is started, but this does not occur always. I'm not able to reproduce it.

[Bruno Luong]

FYI Update 2 has been released

[Jon]

@Bruno Luong I have updated to Update 2, but the warning remains

[Mohamed Eldin]

Perfect it works thank you!

[Leon Thürnau]

Just installed update 3, same warning there. This was a fresh installation and I did not have installed update 1 / 2 before.

[Leon Thürnau]

installed update 4, no warning message there

Answer 5

[Andres]

Note there is now a thread by the MathWorks support team you may want to follow as well

Why do I see a StAXDialectDetector warning after launching MATLAB R2023b

[MathWorks Support Team]

Thank you Andres. Yes, please refer to the linked post and this Bug Report for future updates on this known issue.

[Leon Thürnau]

installed update 4, no warning message there

[Debby]

The links above to "Why do I see a StAXDialectDetector warning after launching MATLAB R2023b" and "linked post" appear to be broken.