title: android studio graphic editor no showing the layout picture
body: <p>For some reason on the project I am working on in Android Studio the XML graphic editor has stopped showing me the picture of the screen layout. The app itself works fine and the layout woks fine on my device, but I don't have a picture of it on my computer screen in the editor. </p>
  
  <p>The editor shows a error <strong>Rendering Problem - Exception raised during rendering</strong><br>
  in the details it shows me a stack trace of a <strong>java.lang.NullPointerException</strong>, and it tip is to try and refresh the layout, but that doesn't work. I tried to refresh, to rebuild, and every other kind of refresh possible but nothing works. I checked other projects that I had worked on and thy where OK the graphics  was fine, but not on my current project. So I need help finding the problem.  </p>
  
  <pre><code>java.lang.NullPointerException
  at android.graphics.BidiRenderer.getScriptFont(BidiRenderer.java:290)
  at android.graphics.BidiRenderer.getScriptRuns(BidiRenderer.java:280)
  at android.graphics.BidiRenderer.renderText(BidiRenderer.java:133)
  at android.graphics.BidiRenderer.renderText(BidiRenderer.java:108)
  at android.graphics.Paint_Delegate.measureText(Paint_Delegate.java:1310)
  at android.graphics.Paint_Delegate.nGetTextAdvances(Paint_Delegate.java:972)
  at android.graphics.Paint_Delegate.nGetRunAdvance(Paint_Delegate.java:1147)
  at android.graphics.Paint.nGetRunAdvance(Paint.java)
  at android.graphics.Paint.getRunAdvance(Paint.java:2729)
  at android.text.TextLine.getRunAdvance(TextLine.java:729)
  at android.text.TextLine.handleText(TextLine.java:778)
  at android.text.TextLine.handleRun(TextLine.java:1018)
  at android.text.TextLine.measureRun(TextLine.java:417)
  at android.text.TextLine.measure(TextLine.java:310)
  at android.text.TextLine.metrics(TextLine.java:281)
  at android.text.Layout.measurePara(Layout.java:1966)
  at android.text.Layout.getDesiredWidthWithLimit(Layout.java:186)
  at android.widget.TextView.onMeasure(TextView.java:8168)
  at android.view.View.measure(View.java:22035)
  at android.widget.Toolbar.measureChildCollapseMargins(Toolbar.java:1548)
  at android.widget.Toolbar.onMeasure(Toolbar.java:1662)
  at android.view.View.measure(View.java:22035)
  at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6622)
  at android.widget.FrameLayout.onMeasure(FrameLayout.java:185)
  at com.android.internal.widget.ActionBarContainer.onMeasure(ActionBarContainer.java:291)
  at android.view.View.measure(View.java:22035)
  at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6622)
  at com.android.internal.widget.ActionBarOverlayLayout.onMeasure(ActionBarOverlayLayout.java:378)
  at android.view.View.measure(View.java:22035)
  at android.widget.RelativeLayout.measureChildHorizontal(RelativeLayout.java:715)
  at android.widget.RelativeLayout.onMeasure(RelativeLayout.java:461)
  at android.view.View.measure(View.java:22035)
  at com.android.layoutlib.bridge.impl.RenderSessionImpl.measureView(RenderSessionImpl.java:590)
  at com.android.layoutlib.bridge.impl.RenderSessionImpl.inflate(RenderSessionImpl.java:343)
  at com.android.layoutlib.bridge.Bridge.createSession(Bridge.java:384)
  at com.android.tools.idea.layoutlib.LayoutLibrary.createSession(LayoutLibrary.java:193)
  at com.android.tools.idea.rendering.RenderTask.createRenderSession(RenderTask.java:547)
  at com.android.tools.idea.rendering.RenderTask.lambda$inflate$3(RenderTask.java:681)
  at java.util.concurrent.FutureTask.run(FutureTask.java:266)
  at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
  at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
  at java.lang.Thread.run(Thread.java:745)
  </code></pre>