Hi,
I am using Debian 13 Trixie operating system.
I wish to operate mine own App Inventor instance to develope Android apps.
I followed the instructions described here: appinventor-sources
The installation was successful, but one dependency remained unsatisfied.
When I ran the following command:
/usr/lib/google-cloud-sdk/bin/java_dev_appserver.sh --port=8888 --address=0.0.0.0 appengine/build/war/
I got this error message:
This action requires the installation of components: [app-engine-java]
Traceback (most recent call last):
File "/usr/lib/google-cloud-sdk/bin/bootstrapping/java_dev_appserver.py", line 50, in <module>
main()
~~~~^^
File "/usr/lib/google-cloud-sdk/bin/bootstrapping/java_dev_appserver.py", line 38, in main
update_manager.UpdateManager.EnsureInstalledAndRestart(
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^
['app-engine-java'],
^^^^^^^^^^^^^^^^^^^^
command=__file__)
^^^^^^^^^^^^^^^^^
File "/usr/lib/google-cloud-sdk/lib/googlecloudsdk/core/updater/update_manager.py", line 273, in EnsureInstalledAndRestart
return manager._EnsureInstalledAndRestart(components, msg, command)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/lib/google-cloud-sdk/lib/googlecloudsdk/core/updater/update_manager.py", line 1531, in _EnsureInstalledAndRestart
if not self.Install(components, throw_if_unattended=True,
~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
restart_args=restart_args):
^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/lib/google-cloud-sdk/lib/googlecloudsdk/core/updater/update_manager.py", line 955, in Install
return self.Update(
~~~~~~~~~~~^
components,
^^^^^^^^^^^
throw_if_unattended=throw_if_unattended,
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
version=version,
^^^^^^^^^^^^^^^^
restart_args=restart_args)
^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/lib/google-cloud-sdk/lib/googlecloudsdk/core/updater/update_manager.py", line 986, in Update
self._CheckIfDisabledAndThrowError(
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^
components=update_seed, command='update')
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/lib/google-cloud-sdk/lib/googlecloudsdk/core/updater/update_manager.py", line 603, in _CheckIfDisabledAndThrowError
raise UpdaterDisabledError(mapping_message)
googlecloudsdk.core.updater.update_manager.UpdaterDisabledError:
You cannot perform this action because the Google Cloud CLI component manager
is disabled for this installation. You can run the following command
to achieve the same result for this installation:
sudo apt-get install google-cloud-cli-app-engine-java
So I followed the advice and installed the [app-engine-java] component:
sudo apt-get install google-cloud-cli-app-engine-java
Then I ran the command again:
/usr/lib/google-cloud-sdk/bin/java_dev_appserver.sh --port=8888 --address=0.0.0.0 appengine/build/war/
but now I got the following error message:
Error: LinkageError occurred while loading main class com.google.appengine.tools.KickStart
java.lang.UnsupportedClassVersionError: com/google/appengine/tools/KickStart has been compiled by a more recent version of the Java Runtime (class file version 61.0), this version of the Java Runtime only recognizes class file versions up to 55.0
So, what can I do now to solve this problem?
I appreciate all advice!
Postscript:
I installed the openjdk-11 version using sdkman!
java -version
openjdk version "21.0.9" 2025-10-21
OpenJDK Runtime Environment (build 21.0.9+10-Debian-1deb13u1)
OpenJDK 64-Bit Server VM (build 21.0.9+10-Debian-1deb13u1, mixed mode, sharing)
Oops, I didn't install this using sdkman!
Now I run in
~/appinventor-sources/appinventor/
directory
sdk use java 11.0.29-tem
Using java version 11.0.29-tem in this shell.
and run again the command:
/usr/lib/google-cloud-sdk/bin/java_dev_appserver.sh --port=8888 --address=0.0.0.0 appengine/build/war/
and get the following error message:
Error: LinkageError occurred while loading main class com.google.appengine.tools.KickStart
java.lang.UnsupportedClassVersionError: com/google/appengine/tools/KickStart has been compiled by a more recent version of the Java Runtime (class file version 61.0), this version of the Java Runtime only recognizes class file versions up to 55.0
--
Sincerely, Paul