A Null Pointer Exception arises under two conditions:
There is no Extension project to be exported
If no project exists under the Package Explorer (or no Extension project is selected under the Package Explorer) and you go File->Export->LibreOffice package.
!ENTRY org.eclipse.ui 4 0 2018-02-28 17:44:34.662
!MESSAGE Unhandled event loop exception
!STACK 0
java.lang.NullPointerException
at org.libreoffice.ide.eclipse.core.gui.PackageContentSelector.getDefaultContent(PackageContentSelector.java:145)
at org.libreoffice.ide.eclipse.core.gui.PackageContentSelector.loadDefaults(PackageContentSelector.java:109)
at org.libreoffice.ide.eclipse.core.wizards.pages.UnoPackageExportPage.loadData(UnoPackageExportPage.java:149)
at org.libreoffice.ide.eclipse.core.wizards.pages.UnoPackageExportPage.createControl(UnoPackageExportPage.java:129)
at org.eclipse.jface.wizard.Wizard.createPageControls(Wizard.java:175)
at org.eclipse.jface.wizard.WizardDialog.createPageControls(WizardDialog.java:696)
at org.eclipse.jface.wizard.WizardDialog.setWizard(WizardDialog.java:1144)
at org.eclipse.jface.wizard.WizardDialog.updateForPage(WizardDialog.java:1197)
at org.eclipse.jface.wizard.WizardDialog.lambda$2(WizardDialog.java:1185)
at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:70)
at org.eclipse.jface.wizard.WizardDialog.showPage(WizardDialog.java:1185)
at org.eclipse.jface.wizard.WizardDialog.nextPressed(WizardDialog.java:876)
at org.eclipse.jface.wizard.WizardDialog.buttonPressed(WizardDialog.java:419)
at org.eclipse.jface.dialogs.Dialog$2.widgetSelected(Dialog.java:618)
at org.eclipse.swt.widgets.TypedListener.handleEvent(TypedListener.java:249)
at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
A Null Pointer Exception arises under two conditions:
!ENTRY org.eclipse.ui 4 0 2018-02-28 17:44:34.662 !MESSAGE Unhandled event loop exception !STACK 0 java.lang.NullPointerException at org.libreoffice.ide.eclipse.core.gui.PackageContentSelector.getDefaultContent(PackageContentSelector.java:145) at org.libreoffice.ide.eclipse.core.gui.PackageContentSelector.loadDefaults(PackageContentSelector.java:109) at org.libreoffice.ide.eclipse.core.wizards.pages.UnoPackageExportPage.loadData(UnoPackageExportPage.java:149) at org.libreoffice.ide.eclipse.core.wizards.pages.UnoPackageExportPage.createControl(UnoPackageExportPage.java:129) at org.eclipse.jface.wizard.Wizard.createPageControls(Wizard.java:175) at org.eclipse.jface.wizard.WizardDialog.createPageControls(WizardDialog.java:696) at org.eclipse.jface.wizard.WizardDialog.setWizard(WizardDialog.java:1144) at org.eclipse.jface.wizard.WizardDialog.updateForPage(WizardDialog.java:1197) at org.eclipse.jface.wizard.WizardDialog.lambda$2(WizardDialog.java:1185) at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:70) at org.eclipse.jface.wizard.WizardDialog.showPage(WizardDialog.java:1185) at org.eclipse.jface.wizard.WizardDialog.nextPressed(WizardDialog.java:876) at org.eclipse.jface.wizard.WizardDialog.buttonPressed(WizardDialog.java:419) at org.eclipse.jface.dialogs.Dialog$2.widgetSelected(Dialog.java:618) at org.eclipse.swt.widgets.TypedListener.handleEvent(TypedListener.java:249) at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)