Java Eclipse android-XML editor (graphic display) is not working

[Heather]

I'm developing some apps for Android on Java Eclipse. As for now everything was ok, but today suddenly the layout graphic display stopped working, no matter if I try to create new layout or try to open existing one. It shows No XML content. Please add a root view or layout to your document. error. I tried to follow android sdk main.out.xml parsing error? instructions, but I have no XSL option inEclipse -> Window -> Preferences -> Run/Debug -> Launching -> Lauch Configuration -> Filter checked launch configuration types. I also don't have any .out.xml file.Here's my XML and manifest file.\[code\]<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" > <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_centerHorizontal="true" android:layout_centerVertical="true" android:text="@string/hello_world" tools:context=".FirstScreenActivity" /></RelativeLayout><manifest xmlns:android="http://schemas.android.com/apk/res/android" package="s.manipulator" android:versionCode="1" android:versionName="1.0" > <uses-sdk android:minSdkVersion="14" android:targetSdkVersion="15" /> <application android:icon="@drawable/ic_launcher" android:label="@string/app_name" android:theme="@style/AppTheme" > <activity android:name=".FirstScreenActivity" android:label="@string/title_activity_first_screen" > <meta-data android:name="android.support.PARENT_ACTIVITY" android:value="http://stackoverflow.com/questions/13779144/android.app.LauncherActivity" /> </activity> <activity android:name=".MainMenuActivity" android:label="@string/title_activity_main_menu" > <meta-data android:name="android.support.PARENT_ACTIVITY" android:value="http://stackoverflow.com/questions/13779144/s.manipulator.FirstScreenActivity" /> </activity> </application></manifest>\[/code\]