Font asset not found roboto_medium.ttf

[dastan1302]

java.lang.RuntimeException: Font asset not found roboto_medium.ttf
at android.graphics.Typeface.createFromAsset(Typeface.java:190)
at co.mobiwise.library.MaskProgressView.init(MaskProgressView.java:229)
at co.mobiwise.library.MaskProgressView.(MaskProgressView.java:181)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:422)
at org.jetbrains.android.uipreview.ViewLoader.createNewInstance(ViewLoader.java:458)
at org.jetbrains.android.uipreview.ViewLoader.loadClass(ViewLoader.java:170)
at org.jetbrains.android.uipreview.ViewLoader.loadView(ViewLoader.java:103)
at com.android.tools.idea.rendering.LayoutlibCallbackImpl.loadView(LayoutlibCallbackImpl.java:170)
at android.view.BridgeInflater.loadCustomView(BridgeInflater.java:218)
at android.view.BridgeInflater.createViewFromTag(BridgeInflater.java:145)
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:704)
at android.view.LayoutInflater.rInflate_Original(LayoutInflater.java:835)
at android.view.LayoutInflater_Delegate.rInflate(LayoutInflater_Delegate.java:70)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:811)
at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:798)
at android.view.LayoutInflater.rInflate_Original(LayoutInflater.java:838)
at android.view.LayoutInflater_Delegate.rInflate(LayoutInflater_Delegate.java:70)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:811)
at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:798)
at android.view.LayoutInflater.inflate(LayoutInflater.java:515)
at android.view.LayoutInflater.inflate(LayoutInflater.java:394)
at com.android.layoutlib.bridge.impl.RenderSessionImpl.inflate(RenderSessionImpl.java:223)
at com.android.layoutlib.bridge.Bridge.createSession(Bridge.java:426)
at com.android.ide.common.rendering.LayoutLibrary.createSession(LayoutLibrary.java:350)
at com.android.tools.idea.rendering.RenderTask$2.compute(RenderTask.java:510)
at com.android.tools.idea.rendering.RenderTask$2.compute(RenderTask.java:498)
at com.intellij.openapi.application.impl.ApplicationImpl.runReadAction(ApplicationImpl.java:888)
at com.android.tools.idea.rendering.RenderTask.createRenderSession(RenderTask.java:498)
at com.android.tools.idea.rendering.RenderTask.access$600(RenderTask.java:72)
at com.android.tools.idea.rendering.RenderTask$3.call(RenderTask.java:610)
at com.android.tools.idea.rendering.RenderTask$3.call(RenderTask.java:607)
at com.android.tools.idea.rendering.RenderService.runRenderAction(RenderService.java:362)
at com.android.tools.idea.rendering.RenderTask.render(RenderTask.java:607)
at com.android.tools.idea.rendering.RenderTask.render(RenderTask.java:629)
at org.jetbrains.android.uipreview.AndroidLayoutPreviewToolWindowManager.doRender(AndroidLayoutPreviewToolWindowManager.java:652)
at org.jetbrains.android.uipreview.AndroidLayoutPreviewToolWindowManager.access$1700(AndroidLayoutPreviewToolWindowManager.java:80)
at org.jetbrains.android.uipreview.AndroidLayoutPreviewToolWindowManager$7$1.run(AndroidLayoutPreviewToolWindowManager.java:594)
at com.intellij.openapi.progress.impl.CoreProgressManager$2.run(CoreProgressManager.java:152)
at com.intellij.openapi.progress.impl.CoreProgressManager.registerIndicatorAndRun(CoreProgressManager.java:452)
at com.intellij.openapi.progress.impl.CoreProgressManager.executeProcessUnderProgress(CoreProgressManager.java:402)
at com.intellij.openapi.progress.impl.ProgressManagerImpl.executeProcessUnderProgress(ProgressManagerImpl.java:54)
at com.intellij.openapi.progress.impl.CoreProgressManager.runProcess(CoreProgressManager.java:137)
at org.jetbrains.android.uipreview.AndroidLayoutPreviewToolWindowManager$7.run(AndroidLayoutPreviewToolWindowManager.java:589)
at com.intellij.util.ui.update.MergingUpdateQueue.execute(MergingUpdateQueue.java:320)
at com.intellij.util.ui.update.MergingUpdateQueue.execute(MergingUpdateQueue.java:310)
at com.intellij.util.ui.update.MergingUpdateQueue$2.run(MergingUpdateQueue.java:254)
at com.intellij.util.ui.update.MergingUpdateQueue.flush(MergingUpdateQueue.java:269)
at com.intellij.util.ui.update.MergingUpdateQueue.flush(MergingUpdateQueue.java:227)
at com.intellij.util.ui.update.MergingUpdateQueue.run(MergingUpdateQueue.java:217)
at com.intellij.util.concurrency.QueueProcessor.runSafely(QueueProcessor.java:238)
at com.intellij.util.Alarm$Request$1.run(Alarm.java:351)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
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)