Hallo Anselm,
kannst Du bitte mal in die Datei ~/.fakturama2/.metadata/.log schauen, ob da dieselbe NullpointerException steht? Da bräuchte ich mal die Zeilen drumherum...

ich hoffe es hilft!

!SESSION 2018-07-03 02:11:20.208 -----------------------------------------------
eclipse.buildId=2.0.2.1
java.version=1.8.0_172
java.vendor=Oracle Corporation
BootLoader constants: OS=win32, ARCH=x86_64, WS=win32, NL=de_DE
Command-line arguments: -os win32 -ws win32 -arch x86_64

!ENTRY org.eclipse.e4.ui.workbench 4 0 2018-07-03 02:11:33.129
!MESSAGE Unable to load class 'com.sebulli.fakturama.handlers.NewProductHandler' from bundle '882'
!STACK 0
java.lang.ClassNotFoundException: com.sebulli.fakturama.handlers.NewProductHandler cannot be found by com.sebulli.fakturama.rcp_2.0.2.1
	at org.eclipse.osgi.internal.loader.BundleLoader.findClassInternal(BundleLoader.java:484)
	at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:395)
	at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:387)
	at org.eclipse.osgi.internal.loader.ModuleClassLoader.loadClass(ModuleClassLoader.java:150)
	at java.lang.ClassLoader.loadClass(Unknown Source)
	at org.eclipse.osgi.internal.framework.EquinoxBundle.loadClass(EquinoxBundle.java:564)
	at org.eclipse.e4.ui.internal.workbench.ReflectionContributionFactory.createFromBundle(ReflectionContributionFactory.java:103)
	at org.eclipse.e4.ui.internal.workbench.ReflectionContributionFactory.doCreate(ReflectionContributionFactory.java:74)
	at org.eclipse.e4.ui.internal.workbench.ReflectionContributionFactory.create(ReflectionContributionFactory.java:56)
	at com.sebulli.fakturama.addons.HandlerProcessingAddon.processActiveHandler(HandlerProcessingAddon.java:193)
	at com.sebulli.fakturama.addons.HandlerProcessingAddon.initialize(HandlerProcessingAddon.java:101)
	at com.sebulli.fakturama.addons.HandlerProcessingAddon$1.run(HandlerProcessingAddon.java:55)
	at org.eclipse.jface.operation.ModalContext$ModalContextThread.run(ModalContext.java:119)

!ENTRY org.eclipse.e4.ui.workbench 1 0 2018-07-03 02:11:34.625
!MESSAGE create Document list part

!ENTRY org.eclipse.e4.ui.workbench 4 0 2018-07-03 02:11:35.559
!MESSAGE No command found for com.sebulli.fakturama.command.webShopImport (Webshop). Please check your Applicationmodel!

!ENTRY org.eclipse.e4.ui.workbench 1 0 2018-07-03 02:11:56.125
!MESSAGE create Product list part

!ENTRY org.eclipse.e4.ui.workbench 1 0 2018-07-03 02:11:58.516
!MESSAGE create DocumentItem list part

!ENTRY org.eclipse.e4.ui.workbench 1 0 2018-07-03 02:12:00.323
!MESSAGE create Product list part

!ENTRY org.eclipse.e4.ui.workbench 4 0 2018-07-03 02:12:01.504
!MESSAGE Internal Error
!STACK 0
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.ui.internal.di.UIEventObjectSupplier$UIEventHandler$1.run(UIEventObjectSupplier.java:64)
	at org.eclipse.swt.widgets.RunnableLock.run(RunnableLock.java:37)
	at org.eclipse.swt.widgets.Synchronizer.runAsyncMessages(Synchronizer.java:182)
	at org.eclipse.swt.widgets.Display.runAsyncMessages(Display.java:4213)
	at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3820)
	at org.eclipse.jface.window.Window.runEventLoop(Window.java:818)
	at org.eclipse.jface.window.Window.open(Window.java:794)
	at com.sebulli.fakturama.parts.itemlist.ItemListBuilder$1.mouseDown(ItemListBuilder.java:126)
	at org.eclipse.swt.widgets.TypedListener.handleEvent(TypedListener.java:193)
	at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:86)
	at org.eclipse.swt.widgets.Display.sendEvent(Display.java:4428)
	at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1079)
	at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:4238)
	at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3817)
	at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$5.run(PartRenderingEngine.java:1150)
	at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:336)
	at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.run(PartRenderingEngine.java:1039)
	at org.eclipse.e4.ui.internal.workbench.E4Workbench.createAndRunUI(E4Workbench.java:153)
	at org.eclipse.e4.ui.internal.workbench.swt.E4Application.start(E4Application.java:162)
	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 sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
	at java.lang.reflect.Method.invoke(Unknown Source)
	at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:653)
	at org.eclipse.equinox.launcher.Main.basicRun(Main.java:590)
	at org.eclipse.equinox.launcher.Main.run(Main.java:1499)
Caused by: java.lang.NullPointerException
	at com.sebulli.fakturama.util.ProductUtil.getPriceByQuantity(ProductUtil.java:86)
	at com.sebulli.fakturama.util.DocumentItemUtil.from(DocumentItemUtil.java:53)
	at com.sebulli.fakturama.parts.DocumentEditor.addItemsToItemList(DocumentEditor.java:2912)
	at com.sebulli.fakturama.parts.DocumentEditor.handleDialogSelection(DocumentEditor.java:2834)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
	at java.lang.reflect.Method.invoke(Unknown Source)
	at org.eclipse.e4.core.internal.di.MethodRequestor.execute(MethodRequestor.java:55)
	... 31 more

!ENTRY org.eclipse.e4.ui.workbench 1 0 2018-07-03 02:12:01.606
!MESSAGE Saving NatTable state to fakturamaviews.properties

!ENTRY org.eclipse.e4.ui.workbench 1 0 2018-07-03 02:12:04.998
!MESSAGE Saving NatTable state to fakturamaviews.properties

!ENTRY org.eclipse.e4.ui.workbench 1 0 2018-07-03 02:12:05.090
!MESSAGE Saving NatTable state to fakturamaviews.properties

!ENTRY org.eclipse.e4.ui.workbench 1 0 2018-07-03 02:12:05.107
!MESSAGE Saving NatTable state to fakturamaviews.properties

Gibts schon Fortschritte bei der Fehleranalyse? Habe ich am Ende etwas falsch gemacht?

Nein, ich hab das noch nicht gefunden. Es hängt irgendwie mit der Preisberechnung zusammen. Verwendest Du Staffelpreise?

Nein keine Staffelpreise, allerdings habe gesehen, dass die CSV nicht wieder ordentlich in Libre Office importiert werden können, vielleicht werden die Zeilen nicht ordentlich getrennt...

verwunderlich dann aber warum zumindest Produkttitel ordentlich übernommen werden...

Also ich habe nochmal geguckt, die CSV ist soweit fehlerfrei... woran kann es noch liegen? Kann ich die Einträge irgendwie manuell in die Datenbank bekommen?