ALL Capella programs stopped working --> Error Message / Need Help

Hello,
The error appeared, I believe, after desactivating/unreferencing an extension through Kitalpha manager inside A Capella Studio RUNTIME pointing at a Capella workspace.

→ Now, Opening any Capella lead to an error, that says: “… go read metalada/log… etc”, even creating a NEW FRESH installation of Capella, would not work. Every Capella 1.4 lead to an error and would not run at all.

The log is long and contains this lines among others:

 !ENTRY org.eclipse.core.jobs 2 2 2022-09-09 10:37:58.179
!MESSAGE Job found still running after platform shutdown.  Jobs should be canceled by the plugin that scheduled them during shutdown: org.eclipse.ui.internal.ide.IDEWorkbenchActivityHelper$2

 !ENTRY org.eclipse.core.jobs 2 2 2022-09-09 10:37:58.180
!MESSAGE Job found still running after platform shutdown.  Jobs should be canceled by the plugin that scheduled them during shutdown: org.eclipse.egit.ui.Activator$1

!MESSAGE Unhandled event loop exception
!STACK 0
org.eclipse.swt.SWTException: Widget is disposed
	at org.eclipse.swt.SWT.error(SWT.java:4533)
	at org.eclipse.swt.SWT.error(SWT.java:4448)
	at org.eclipse.swt.SWT.error(SWT.java:4419)

 !SESSION 2019-10-17 08:32:38.806 -----------------------------------------------
eclipse.buildId=unknown
java.version=1.8.0_121
java.vendor=Oracle Corporation
BootLoader constants: OS=win32, ARCH=x86_64, .....
Command-line arguments:  -os win32 -ws win32 -arch x86_64

!ENTRY org.eclipse.amalgam.explorer.activity.ui 4 0 2019-10-17 10:28:19.782
!MESSAGE Cannot load state of Activity Explorer for /In-Flight Entertainment System/In-Flight Entertainment System.aird

 !ENTRY org.polarsys.capella.common.platform.sirius.ted 2 0 2019-10-17 10:59:15.531
!MESSAGE Error while executing a command:
!STACK 0
java.lang.IllegalArgumentException: Argument cannot be null


 !ENTRY org.eclipse.core.databinding 4 0 2019-10-17 14:19:47.190
!MESSAGE An error occurred while setting the value.
!STACK 0
java.lang.UnsupportedOperationException

 !ENTRY org.eclipse.core.databinding 4 0 2019-10-17 14:21:03.196
!MESSAGE An error occurred while setting the value.
!STACK 0
java.lang.UnsupportedOperationException
	at org.eclipse.core.databinding.observable.value.AbstractObservableValue.doSetValue(AbstractObservableValue.java:76)
	at org.eclipse.core.databinding.observable.value.AbstractObservableValue.setValue(AbstractObservableValue.java:66)
	at org.eclipse.core.databinding.UpdateValueStrategy.doSet(UpdateValueStrategy.java:469)
	at org.eclipse.core.databinding.ValueBinding$3$1.run(ValueBinding.java:210)
	at org.eclipse.core.databinding.observable.Realm$1.run(Realm.java:149)
	at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)
- !ENTRY org.eclipse.help.base 2 0 2019-10-17 14:33:14.106
!MESSAGE Unable to consume Lucene index from bundle 'org.eclipse.platform.doc.isv_4.7.3.v20180301-0825 [343]'. The index should be rebuilt with Lucene 6.1.

!ENTRY org.eclipse.help.base 2 0 2019-10-17 14:33:14.116
!MESSAGE Unable to consume Lucene index from bundle 'org.eclipse.jdt.doc.user_3.13.51.v20171124-0639 [292]'. The index should be rebuilt with Lucene 6.1.

!ENTRY org.eclipse.help.base 2 0 2019-10-17 14:33:14.125
!MESSAGE Unable to consume Lucene index from bundle 'org.eclipse.jdt.doc.isv_3.13.52.v20180301-0825 [291]'. The index should be rebuilt with Lucene 6.1.

!ENTRY org.eclipse.help.base 2 0 2019-10-17 14:33:14.135
!MESSAGE Unable to consume Lucene index from bundle 'org.eclipse.pde.doc.user_3.13.3.v20180301-0825 [328]'. The index should be rebuilt with Lucene 6.1.

!ENTRY org.eclipse.help.base 2 0 2019-10-17 14:33:14.144
!MESSAGE Unable to consume Lucene index from bundle 'org.eclipse.platform.doc.user_4.7.3.v20171222-0602 [344]'. The index should be rebuilt with Lucene 6.1.

!ENTRY org.eclipse.help.base 2 0 2019-10-17 14:33:14.155
!MESSAGE Unable to consume Lucene index from bundle 'org.eclipse.emf.doc_2.10.0.v20170609-0928 [154]'. The index should be rebuilt with Lucene 6.1.

 Caused by: java.lang.NoClassDefFoundError: Could not initialize class org.polarsys.capella.core.commands.preferences.util.PreferencesHelper
	at org.polarsys.capella.core.commands.preferences.service.AbstractPreferencesInitializer.<init>(AbstractPreferencesInitializer.java:38)
	at org.polarsys.capella.common.tools.report.appenders.usage.preferences.PreferencesInitializer.<init>(PreferencesInitializer.java:27)
	at org.polarsys.capella.common.tools.report.appenders.usage.UsageAppenderPlugin.start(UsageAppenderPlugin.java:43)
	at org.eclipse.osgi.internal.framework.BundleContextImpl$3.run(BundleContextImpl.java:842)
	at org.eclipse.osgi.internal.framework.BundleContextImpl$3.run(BundleContextImpl.java:1)
	at java.base/java.security.AccessController.doPrivileged(Native Method)
	at org.eclipse.osgi.internal.framework.BundleContextImpl.startActivator(BundleContextImpl.java:834)
	... 42 more

This goes for 7500 lines…


The Capella version used is Capella 1.4

__
Any idea what happened and how to fix it?
Thanks