Eclipse Photon Marketplace client can not be opened - eclipse

Question

When running Eclipse Photon with Java 18.3 I can not open Marketplace client.
And I have no errors like in Eclipse Photon - Eclipse Marketplace not launching (and spaces in installation path also).
Only thing that is present in .log file in .metadata folder of my eclipse-workspace is:
org.eclipse.e4.core.di.InjectionException: java.lang.NullPointerException
at org.eclipse.e4.core.internal.di.MethodRequestor.execute(MethodRequestor.java:65)
at org.eclipse.e4.core.internal.di.InjectorImpl.invokeUsingClass(InjectorImpl.java:318)
at org.eclipse.e4.core.internal.di.InjectorImpl.invoke(InjectorImpl.java:252)
at org.eclipse.e4.core.contexts.ContextInjectionFactory.invoke(ContextInjectionFactory.java:161)
at org.eclipse.e4.core.commands.internal.HandlerServiceHandler.execute(HandlerServiceHandler.java:152)
at org.eclipse.core.commands.Command.executeWithChecks(Command.java:494)
at org.eclipse.core.commands.ParameterizedCommand.executeWithChecks(ParameterizedCommand.java:487)
at org.eclipse.e4.core.commands.internal.HandlerServiceImpl.executeHandler(HandlerServiceImpl.java:204)
at org.eclipse.e4.ui.workbench.renderers.swt.HandledContributionItem.executeItem(HandledContributionItem.java:433)
at org.eclipse.e4.ui.workbench.renderers.swt.AbstractContributionItem.handleWidgetSelection(AbstractContributionItem.java:446)
at org.eclipse.e4.ui.workbench.renderers.swt.AbstractContributionItem.lambda$2(AbstractContributionItem.java:472)
at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:86)
at org.eclipse.swt.widgets.Display.sendEvent(Display.java:5686)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1370)
at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:4940)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:4518)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$5.run(PartRenderingEngine.java:1170)
at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:336)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.run(PartRenderingEngine.java:1059)
at org.eclipse.e4.ui.internal.workbench.E4Workbench.createAndRunUI(E4Workbench.java:153)
at org.eclipse.ui.internal.Workbench.lambda$3(Workbench.java:667)
at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:336)
at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:597)
at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:148)
at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:152)
at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:196)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:134)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:104)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:388)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:243)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:564)
at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:656)
at org.eclipse.equinox.launcher.Main.basicRun(Main.java:592)
at org.eclipse.equinox.launcher.Main.run(Main.java:1498)
at org.eclipse.equinox.launcher.Main.main(Main.java:1471)
Caused by: java.lang.NullPointerException
at org.eclipse.epp.internal.mpc.ui.css.StyleHelper.applyStyles(StyleHelper.java:184)
at org.eclipse.epp.internal.mpc.ui.wizards.CatalogSwitcher.refreshSelection(CatalogSwitcher.java:189)
at org.eclipse.epp.internal.mpc.ui.wizards.CatalogSwitcher.setSelection(CatalogSwitcher.java:178)
at org.eclipse.epp.internal.mpc.ui.wizards.MarketplacePage.createMarketplaceSwitcher(MarketplacePage.java:660)
at org.eclipse.epp.internal.mpc.ui.wizards.MarketplacePage.createControl(MarketplacePage.java:261)
at org.eclipse.jface.wizard.Wizard.createPageControls(Wizard.java:176)
at org.eclipse.jface.wizard.WizardDialog.createPageControls(WizardDialog.java:682)
at org.eclipse.jface.wizard.WizardDialog.createContents(WizardDialog.java:574)
at org.eclipse.jface.window.Window.create(Window.java:426)
at org.eclipse.jface.dialogs.Dialog.create(Dialog.java:1096)
at org.eclipse.jface.window.Window.open(Window.java:783)
at org.eclipse.epp.internal.mpc.ui.commands.AbstractMarketplaceWizardCommand.openWizardDialog(AbstractMarketplaceWizardCommand.java:145)
at org.eclipse.epp.internal.mpc.ui.commands.AbstractMarketplaceWizardCommand.execute(AbstractMarketplaceWizardCommand.java:72)
at org.eclipse.ui.internal.handlers.HandlerProxy.execute(HandlerProxy.java:291)
at org.eclipse.ui.internal.handlers.E4HandlerProxy.execute(E4HandlerProxy.java:93)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:564)
at org.eclipse.e4.core.internal.di.MethodRequestor.execute(MethodRequestor.java:55)
... 37 more

Answer 1

Caused by: java.lang.NullPointerException
at org.eclipse.epp.internal.mpc.ui.css.StyleHelper.applyStyles(StyleHelper.java:184)
This exception's cause pointing that something wrong with styling I think.
So problem disappeared, after enabling themes:
Window -> Preferences -> General -> Appearance -> Enable theming.