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0 votes

Hi, I have two servers installed the same way. Everything was working fine until the last Web Panel update.

On server 1, the QR Codes are no longer visible, I reloaded the backup of the ROOT.war file but the problem persists, I reloaded the previous Web Panel version: 5.25.1, still the same problem. The problem only affects the QR Code: I can update the tablets already registered.

On server 2, no problem, everything works correctly.

Where I have a problem, I had to reload a backup from before the update to be able to do an update again, but the problem returns some times after the update but not directly after, for example, yesterday evening before leaving, I reloaded the server backup, I made sure that the QR Codes worked; this morning I checked once again that the QR codes were working, I did the update, the QR Codes were visible then I added app updates in the configurations (Firefox) and I deleted the no longer used application files. After that, the QR codes were no longer readable. Does anyone have a clue for a solution? thank you

by (220 points)

1 Answer

0 votes
When QR code is failed to generate, the error reason is written in the log file: /var/lib/tomcat9/logs/catalina.out. Probably you shouldn't delete the application files.
by (33.0k points)
I can't determine what make the bug after reading the cataline.out log. I gonna backup the server disk again and stay with 5.25.1 for now.
Do you see any stack traces of an exception in the log?
I see a lot of problems from java but I don't have the knowledge to understand the data.

This morning, with the backup everything is working well. I didn't update the Web Panel but I only update the MDM launcher to 5.26 and add it to the configuration as MDM application. Just after that the problem cames back. I resolved by deleting the 5.26 MDM launcher and come back to 5.24 as MDM application.
Version 5.24 and 5.26 should have different version codes. If 5.26 has the same version code, it is probably corrupted, please download it again. When you return back to the previous version, the checksum for it is already calculated by Headwind MDM, so QR code is working. Please check the catalina.out log for errors when you generate the QR code, that's the only way to fix the issue.
Forgot what I said about version code, not enough cafein...

This is the first lines of the catalina.out log :
26-Feb-2024 05:00:14.872 INFO [Thread-8] org.apache.coyote.AbstractProtocol.pause Protocol handler ["http-nio-8080"] is paused
26-Feb-2024 05:00:14.877 INFO [Thread-8] org.apache.coyote.AbstractProtocol.pause Protocol handler ["https-openssl-nio-8443"] is paused
26-Feb-2024 05:00:14.878 INFO [Thread-8] org.apache.catalina.core.StandardService.stopInternal Stopping service [Catalina]
26-Feb-2024 05:00:14.917 INFO [Thread-8] nonapi.io.github.classgraph.classloaderhandler.lifecycle.ServletLifeCycleListener.contextDestroyed Servlet context destroyed -- closing any remaning open ClassGraph ScanResult instances
26-Feb-2024 05:00:14.931 WARNING [Thread-8] org.apache.catalina.loader.WebappClassLoaderBase.clearReferencesJdbc Web application [ROOT] has registered a JDBC driver [org.postgresql.Driver], but does not register it was not unregistered before stopping the application. To avoid a memory leak, the JDBC driver was forcibly unregistered.
26-Feb-2024 05:00:14.942 WARNING [Thread-8] org.apache.catalina.loader.WebappClassLoaderBase.clearReferencesObjectStreamClassCaches Unable to clear weak references from ObjectStreamClass$Caches for web application [ROOT]
I solved the problem by adding the server's internal IP address and the domain name used at etc/hosts
I had to do this to install the other server but as on this one it worked without it, I had not modified anything.

thank you for your help