Can't open forms upgrading Servy from 7.4 to 2022.6.0.3782

Hello,
we recently upgraded Servoy from an old 7.4 to the recent 2022.6.0.3782.

Now I have a problem which don’t allow me to open forms in editor.
I made a clean installation on a new pc importing the workspace with Java 1.8.

Full exception stack trace:

org.json.JSONException: A JSONObject text must begin with '{' at 1 [character 2 line 1]
	at org.json.JSONTokener.syntaxError(JSONTokener.java:435)
	at org.json.JSONObject.<init>(JSONObject.java:198)
	at org.json.JSONObject.<init>(JSONObject.java:323)
	at com.servoy.j2db.util.ServoyJSONObject.<init>(ServoyJSONObject.java:96)
	at com.servoy.j2db.util.ServoyJSONObject.<init>(ServoyJSONObject.java:91)
	at com.servoy.eclipse.designer.editor.palette.VisualFormEditorPaletteFactory.addTemplates(VisualFormEditorPaletteFactory.java:209)
	at com.servoy.eclipse.designer.editor.palette.VisualFormEditorPaletteFactory.getDefaultPaletteCustomization(VisualFormEditorPaletteFactory.java:180)
	at com.servoy.eclipse.designer.editor.palette.VisualFormEditorPaletteFactory.fillPalette(VisualFormEditorPaletteFactory.java:890)
	at com.servoy.eclipse.designer.editor.palette.BaseVisualFormEditorPaletteFactory.createPalette(BaseVisualFormEditorPaletteFactory.java:78)
	at com.servoy.eclipse.designer.editor.BaseVisualFormEditorGEFDesignPage.getPaletteRoot(BaseVisualFormEditorGEFDesignPage.java:100)
	at org.eclipse.gef.ui.parts.GraphicalEditorWithFlyoutPalette.setEditDomain(GraphicalEditorWithFlyoutPalette.java:161)
	at com.servoy.eclipse.designer.editor.BaseVisualFormEditorDesignPage.<init>(BaseVisualFormEditorDesignPage.java:94)
	at com.servoy.eclipse.designer.editor.BaseVisualFormEditorGEFDesignPage.<init>(BaseVisualFormEditorGEFDesignPage.java:72)
	at com.servoy.eclipse.designer.editor.VisualFormEditorDesignPage.<init>(VisualFormEditorDesignPage.java:188)
	at com.servoy.eclipse.designer.editor.VisualFormEditor.createGraphicaleditor(VisualFormEditor.java:190)
	at com.servoy.eclipse.designer.editor.BaseVisualFormEditor.createDesignPage(BaseVisualFormEditor.java:880)
	at com.servoy.eclipse.designer.editor.BaseVisualFormEditor.createPages(BaseVisualFormEditor.java:815)
	at com.servoy.eclipse.designer.editor.VisualFormEditor.createPages(VisualFormEditor.java:124)
	at org.eclipse.ui.part.MultiPageEditorPart.createPartControl(MultiPageEditorPart.java:333)
	at org.eclipse.ui.internal.e4.compatibility.CompatibilityPart.createPartControl(CompatibilityPart.java:158)
	at org.eclipse.ui.internal.e4.compatibility.CompatibilityEditor.createPartControl(CompatibilityEditor.java:96)
	at org.eclipse.ui.internal.e4.compatibility.CompatibilityPart.create(CompatibilityPart.java:365)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
	at java.base/java.lang.reflect.Method.invoke(Unknown Source)
	at org.eclipse.e4.core.internal.di.MethodRequestor.execute(MethodRequestor.java:58)
	at org.eclipse.e4.core.internal.di.InjectorImpl.processAnnotated(InjectorImpl.java:995)
	at org.eclipse.e4.core.internal.di.InjectorImpl.processAnnotated(InjectorImpl.java:960)
	at org.eclipse.e4.core.internal.di.InjectorImpl.internalInject(InjectorImpl.java:140)
	at org.eclipse.e4.core.internal.di.InjectorImpl.internalMake(InjectorImpl.java:403)
	at org.eclipse.e4.core.internal.di.InjectorImpl.make(InjectorImpl.java:330)
	at org.eclipse.e4.core.contexts.ContextInjectionFactory.make(ContextInjectionFactory.java:202)
	at org.eclipse.e4.ui.internal.workbench.ReflectionContributionFactory.createFromBundle(ReflectionContributionFactory.java:91)
	at org.eclipse.e4.ui.internal.workbench.ReflectionContributionFactory.doCreate(ReflectionContributionFactory.java:60)
	at org.eclipse.e4.ui.internal.workbench.ReflectionContributionFactory.create(ReflectionContributionFactory.java:42)
	at org.eclipse.e4.ui.workbench.renderers.swt.ContributedPartRenderer.createWidget(ContributedPartRenderer.java:132)
	at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.createWidget(PartRenderingEngine.java:995)
	at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.safeCreateGui(PartRenderingEngine.java:659)
	at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.safeCreateGui(PartRenderingEngine.java:763)
	at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$2.run(PartRenderingEngine.java:728)
	at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:45)
	at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.createGui(PartRenderingEngine.java:712)
	at org.eclipse.e4.ui.internal.workbench.PartServiceImpl.lambda$0(PartServiceImpl.java:105)
	at org.eclipse.e4.ui.services.internal.events.UIEventHandler.lambda$0(UIEventHandler.java:38)
	at org.eclipse.swt.widgets.Synchronizer.syncExec(Synchronizer.java:236)
	at org.eclipse.ui.internal.UISynchronizer.syncExec(UISynchronizer.java:133)
	at org.eclipse.swt.widgets.Display.syncExec(Display.java:4779)
	at org.eclipse.e4.ui.workbench.swt.DisplayUISynchronize.syncExec(DisplayUISynchronize.java:34)
	at org.eclipse.e4.ui.services.internal.events.UIEventHandler.handleEvent(UIEventHandler.java:38)
	at org.eclipse.equinox.internal.event.EventHandlerWrapper.handleEvent(EventHandlerWrapper.java:205)
	at org.eclipse.equinox.internal.event.EventHandlerTracker.dispatchEvent(EventHandlerTracker.java:203)
	at org.eclipse.equinox.internal.event.EventHandlerTracker.dispatchEvent(EventHandlerTracker.java:1)
	at org.eclipse.osgi.framework.eventmgr.EventManager.dispatchEvent(EventManager.java:234)
	at org.eclipse.osgi.framework.eventmgr.ListenerQueue.dispatchEventSynchronous(ListenerQueue.java:151)
	at org.eclipse.equinox.internal.event.EventAdminImpl.dispatchEvent(EventAdminImpl.java:133)
	at org.eclipse.equinox.internal.event.EventAdminImpl.sendEvent(EventAdminImpl.java:75)
	at org.eclipse.equinox.internal.event.EventComponent.sendEvent(EventComponent.java:44)
	at org.eclipse.e4.ui.services.internal.events.EventBroker.send(EventBroker.java:55)
	at org.eclipse.e4.ui.internal.workbench.UIEventPublisher.notifyChanged(UIEventPublisher.java:63)
	at org.eclipse.emf.common.notify.impl.BasicNotifierImpl.eNotify(BasicNotifierImpl.java:424)
	at org.eclipse.e4.ui.model.application.ui.impl.ElementContainerImpl.setSelectedElementGen(ElementContainerImpl.java:170)
	at org.eclipse.e4.ui.model.application.ui.impl.ElementContainerImpl.setSelectedElement(ElementContainerImpl.java:188)
	at org.eclipse.e4.ui.internal.workbench.ModelServiceImpl.showElementInWindow(ModelServiceImpl.java:660)
	at org.eclipse.e4.ui.internal.workbench.ModelServiceImpl.bringToTop(ModelServiceImpl.java:624)
	at org.eclipse.e4.ui.internal.workbench.PartServiceImpl.delegateBringToTop(PartServiceImpl.java:787)
	at org.eclipse.e4.ui.internal.workbench.PartServiceImpl.bringToTop(PartServiceImpl.java:401)
	at org.eclipse.e4.ui.internal.workbench.PartServiceImpl.showPart(PartServiceImpl.java:1261)
	at org.eclipse.ui.internal.WorkbenchPage.busyOpenEditor(WorkbenchPage.java:3207)
	at org.eclipse.ui.internal.WorkbenchPage.lambda$9(WorkbenchPage.java:3097)
	at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:74)
	at org.eclipse.ui.internal.WorkbenchPage.openEditor(WorkbenchPage.java:3095)
	at org.eclipse.ui.internal.WorkbenchPage.openEditor(WorkbenchPage.java:3065)
	at org.eclipse.ui.internal.WorkbenchPage.openEditor(WorkbenchPage.java:3056)
	at com.servoy.eclipse.ui.util.EditorUtil.openFormDesignEditor(EditorUtil.java:235)
	at com.servoy.eclipse.ui.util.EditorUtil.openFormDesignEditor(EditorUtil.java:217)
	at com.servoy.eclipse.ui.views.solutionexplorer.actions.OpenFormEditorAction.run(OpenFormEditorAction.java:59)
	at com.servoy.eclipse.ui.views.solutionexplorer.actions.OpenFormEditorAction.run(OpenFormEditorAction.java:68)
	at org.eclipse.ui.internal.PluginAction.runWithEvent(PluginAction.java:239)
	at org.eclipse.jface.action.ActionContributionItem.handleWidgetSelection(ActionContributionItem.java:580)
	at org.eclipse.jface.action.ActionContributionItem.lambda$4(ActionContributionItem.java:414)
	at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:89)
	at org.eclipse.swt.widgets.Display.sendEvent(Display.java:4243)
	at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1063)
	at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:4060)
	at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3632)
	at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$5.run(PartRenderingEngine.java:1155)
	at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:338)
	at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.run(PartRenderingEngine.java:1046)
	at org.eclipse.e4.ui.internal.workbench.E4Workbench.createAndRunUI(E4Workbench.java:155)
	at org.eclipse.ui.internal.Workbench.lambda$3(Workbench.java:644)
	at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:338)
	at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:551)
	at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:156)
	at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:152)
	at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:203)
	at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:136)
	at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:104)
	at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:401)
	at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:255)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
	at java.base/java.lang.reflect.Method.invoke(Unknown Source)
	at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:659)
	at org.eclipse.equinox.launcher.Main.basicRun(Main.java:596)
	at org.eclipse.equinox.launcher.Main.run(Main.java:1467)

Thanks in advance