STEPS TO REPRODUCE:
1. Have existent non-scala project, say, Python.
2. Click File / Open File
3A. Choose a scala file under project root.
3B. Choose a scala file outside project root.

OBSERVED BEHAVIOR:
A. Exception below.
B. Eclipse editor tab created, but not populated.

Java Model Exception: Java Model Status [git does not exist]
at org.eclipse.jdt.internal.core.JavaElement.newNotPresentException(JavaElement.java:492)
at org.eclipse.jdt.internal.core.JavaModelManager.getPerProjectInfoCheckExistence(JavaModelManager.java:2097)
at org.eclipse.jdt.internal.core.JavaProject.getPerProjectInfo(JavaProject.java:1820)
at org.eclipse.jdt.internal.core.JavaProject.getResolvedClasspath(JavaProject.java:1887)
at scala.tools.eclipse.ScalaProject.scala$tools$eclipse$ScalaProject$$classpath(ScalaProject.scala:98)
at scala.tools.eclipse.ScalaProject.classpath(ScalaProject.scala:93)
at scala.tools.eclipse.ScalaProject.initialize(ScalaProject.scala:305)
at scala.tools.eclipse.ScalaProject$$anon$1.create(ScalaProject.scala:44)
at scala.tools.eclipse.ScalaProject$$anon$1.create(ScalaProject.scala:40)
at scala.tools.eclipse.util.Cached$class.apply(Cached.scala:44)
at scala.tools.eclipse.ScalaProject$$anon$1.apply(ScalaProject.scala:40)
at scala.tools.eclipse.ScalaProject.withPresentationCompiler(ScalaProject.scala:362)
at scala.tools.eclipse.javaelements.ScalaCompilationUnit$class.discard(ScalaCompilationUnit.scala:74)
at scala.tools.eclipse.javaelements.ScalaSourceFile.discard(ScalaSourceFile.scala:40)
at scala.tools.eclipse.javaelements.ScalaCompilationUnit$class.close(ScalaCompilationUnit.scala:78)
at scala.tools.eclipse.javaelements.ScalaSourceFile.close(ScalaSourceFile.scala:40)
at org.eclipse.jdt.internal.core.CompilationUnit.becomeWorkingCopy(CompilationUnit.java:97)
at org.eclipse.jdt.internal.ui.javaeditor.CompilationUnitDocumentProvider.createFileInfo(CompilationUnitDocumentProvider.java:983)
at org.eclipse.ui.editors.text.TextFileDocumentProvider.connect(TextFileDocumentProvider.java:478)
at org.eclipse.jdt.internal.ui.javaeditor.CompilationUnitDocumentProvider.connect(CompilationUnitDocumentProvider.java:1198)
at org.eclipse.ui.texteditor.AbstractTextEditor.doSetInput(AbstractTextEditor.java:4135)
at org.eclipse.ui.texteditor.StatusTextEditor.doSetInput(StatusTextEditor.java:203)
at org.eclipse.ui.texteditor.AbstractDecoratedTextEditor.doSetInput(AbstractDecoratedTextEditor.java:1413)
at org.eclipse.jdt.internal.ui.javaeditor.JavaEditor.internalDoSetInput(JavaEditor.java:2552)
at org.eclipse.jdt.internal.ui.javaeditor.JavaEditor.doSetInput(JavaEditor.java:2525)
at org.eclipse.jdt.internal.ui.javaeditor.CompilationUnitEditor.doSetInput(CompilationUnitEditor.java:1371)
at org.eclipse.ui.texteditor.AbstractTextEditor$19.run(AbstractTextEditor.java:3116)
at org.eclipse.jface.operation.ModalContext.runInCurrentThread(ModalContext.java:464)
at org.eclipse.jface.operation.ModalContext.run(ModalContext.java:372)
at org.eclipse.jface.window.ApplicationWindow$1.run(ApplicationWindow.java:759)
at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:70)
at org.eclipse.jface.window.ApplicationWindow.run(ApplicationWindow.java:756)
at org.eclipse.ui.internal.WorkbenchWindow.run(WorkbenchWindow.java:2579)
at org.eclipse.ui.texteditor.AbstractTextEditor.internalInit(AbstractTextEditor.java:3134)
at org.eclipse.ui.texteditor.AbstractTextEditor.init(AbstractTextEditor.java:3161)
at org.eclipse.ui.internal.EditorManager.createSite(EditorManager.java:798)
at org.eclipse.ui.internal.EditorReference.createPartHelper(EditorReference.java:644)
at org.eclipse.ui.internal.EditorReference.createPart(EditorReference.java:462)
at org.eclipse.ui.internal.WorkbenchPartReference.getPart(WorkbenchPartReference.java:595)
at org.eclipse.ui.internal.EditorReference.getEditor(EditorReference.java:286)
at org.eclipse.ui.internal.WorkbenchPage.busyOpenEditorBatched(WorkbenchPage.java:2857)
at org.eclipse.ui.internal.WorkbenchPage.busyOpenEditor(WorkbenchPage.java:2762)
at org.eclipse.ui.internal.WorkbenchPage.access$11(WorkbenchPage.java:2754)
at org.eclipse.ui.internal.WorkbenchPage$10.run(WorkbenchPage.java:2705)
at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:70)
at org.eclipse.ui.internal.WorkbenchPage.openEditor(WorkbenchPage.java:2701)
at org.eclipse.ui.internal.WorkbenchPage.openEditor(WorkbenchPage.java:2685)
at org.eclipse.ui.internal.WorkbenchPage.openEditor(WorkbenchPage.java:2668)
at org.eclipse.ui.ide.IDE.openEditor(IDE.java:683)
at org.python.pydev.navigator.actions.PyOpenResourceAction.openFiles(PyOpenResourceAction.java:33)
at org.python.pydev.navigator.actions.PyOpenPythonFileAction.run(PyOpenPythonFileAction.java:70)
at org.eclipse.ui.actions.RetargetAction.run(RetargetAction.java:221)
at org.eclipse.ui.navigator.CommonNavigatorManager$3.open(CommonNavigatorManager.java:202)
at org.eclipse.ui.OpenAndLinkWithEditorHelper$InternalListener.open(OpenAndLinkWithEditorHelper.java:48)
at org.eclipse.jface.viewers.StructuredViewer$2.run(StructuredViewer.java:842)
at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)
at org.eclipse.core.runtime.Platform.run(Platform.java:888)
at org.eclipse.ui.internal.JFaceUtil$1.run(JFaceUtil.java:48)
at org.eclipse.jface.util.SafeRunnable.run(SafeRunnable.java:175)
at org.eclipse.jface.viewers.StructuredViewer.fireOpen(StructuredViewer.java:840)
at org.eclipse.jface.viewers.StructuredViewer.handleOpen(StructuredViewer.java:1101)
at org.eclipse.ui.navigator.CommonViewer.handleOpen(CommonViewer.java:467)
at org.eclipse.jface.viewers.StructuredViewer$6.handleOpen(StructuredViewer.java:1205)
at org.eclipse.jface.util.OpenStrategy.fireOpenEvent(OpenStrategy.java:264)
at org.eclipse.jface.util.OpenStrategy.access$2(OpenStrategy.java:258)
at org.eclipse.jface.util.OpenStrategy$1.handleEvent(OpenStrategy.java:298)
at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1176)
at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:3493)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3112)
at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:2418)
at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:2380)
at org.eclipse.ui.internal.Workbench.access$4(Workbench.java:2232)
at org.eclipse.ui.internal.Workbench$5.run(Workbench.java:511)
at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:504)
at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149)
at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:113)
at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:194)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:110)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:79)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:368)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:179)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:616)
at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:559)
at org.eclipse.equinox.launcher.Main.basicRun(Main.java:514)
at org.eclipse.equinox.launcher.Main.run(Main.java:1311)