[Galaxy S II Themes and Apps] cschmitt:
Basically, the runtime complains that it can't find the oat file for Email.apk, and when checking in /cache/dalvik/cache there is no .dex file created for either Email.apk or Exchange2.apk after switching to ART. So probably the ART optimization on boot is failing for Email.apk and Exchange2.apk because they've been modified.

I/ActivityManager( 711): Start proc com.android.email for broadcast com.android.email/.service.EmailBroadcastReceiver: pid=5149 uid=10018 gids={50018, 3003, 1028, 1015}
D/IccSmsInterfaceManager( 3568): [IccSmsInterfaceManager] Calling setGsmBroadcastConfig with 2 configurations
D/IccSmsInterfaceManager( 3568): [IccSmsInterfaceManager] Added cell broadcast subscription for MID range 4356 to 4356 from client com.android.cellbroadcastreceiver
D/IccSmsInterfaceManager( 3568): [IccSmsInterfaceManager] Calling setCellBroadcastActivation(true)
I/art ( 5149): Failed to open oat file from /system/app/Email.odex or /cache/dalvik-cache/system@app@Email.apk@classes.dex.
E/art ( 5149): Failed to open file: /cache/dalvik-cache/system@app@Email.apk@classes.dex
E/art ( 5149): Failed to open locked oat file: /cache/dalvik-cache/system@app@Email.apk@classes.dex
W/art ( 5149): Failed to open dex file: /system/app/Email.apk
D/AndroidRuntime( 5149): Shutting down VM
E/AndroidRuntime( 5149): FATAL EXCEPTION: main
E/AndroidRuntime( 5149): Process: com.android.email, PID: 5149
E/AndroidRuntime( 5149): java.lang.RuntimeException: Unable to instantiate application com.android.email.EmailApplication: java.lang.ClassNotFoundException: Didn't find class "com.android.email.EmailApplication" on path: DexPathList[[zip file "/system/app/Email.apk"],nativeLibraryDirectories=[/vendor/lib, /system/lib]]
E/AndroidRuntime( 5149):	at android.app.LoadedApk.makeApplication(LoadedApk.java:516)
E/AndroidRuntime( 5149):	at android.app.ActivityThread.handleBindApplication(ActivityThread.java:4381)
E/AndroidRuntime( 5149):	at android.app.ActivityThread.access$1500(ActivityThread.java:145)
E/AndroidRuntime( 5149):	at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1266)
E/AndroidRuntime( 5149):	at android.os.Handler.dispatchMessage(Handler.java:102)
E/AndroidRuntime( 5149):	at android.os.Looper.loop(Looper.java:136)
E/AndroidRuntime( 5149):	at android.app.ActivityThread.main(ActivityThread.java:5081)
E/AndroidRuntime( 5149):	at java.lang.reflect.Method.invoke(Native Method)
E/AndroidRuntime( 5149):	at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:781)
E/AndroidRuntime( 5149):	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
E/AndroidRuntime( 5149): Caused by: java.lang.ClassNotFoundException: Didn't find class "com.android.email.EmailApplication" on path: DexPathList[[zip file "/system/app/Email.apk"],nativeLibraryDirectories=[/vendor/lib, /system/lib]]
E/AndroidRuntime( 5149):	at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:56)
E/AndroidRuntime( 5149):	at java.lang.ClassLoader.loadClass(ClassLoader.java:511)
E/AndroidRuntime( 5149):	at java.lang.ClassLoader.loadClass(ClassLoader.java:469)
E/AndroidRuntime( 5149):	at android.app.Instrumentation.newApplication(Instrumentation.java:975)
E/AndroidRuntime( 5149):	at android.app.LoadedApk.makeApplication(LoadedApk.java:511)
E/AndroidRuntime( 5149):	... 9 more
E/AndroidRuntime( 5149):	Suppressed: java.io.IOException: Unable to open dex file: /system/app/Email.apk
E/AndroidRuntime( 5149):	at dalvik.system.DexFile.openDexFileNative(Native Method)
E/AndroidRuntime( 5149):	at dalvik.system.DexFile.openDexFile(DexFile.java:296)
E/AndroidRuntime( 5149):	at dalvik.system.DexFile.<init>(DexFile.java:80)
E/AndroidRuntime( 5149):	at dalvik.system.DexFile.<init>(DexFile.java:59)
E/AndroidRuntime( 5149):	at dalvik.system.DexPathList.loadDexFile(DexPathList.java:263)
E/AndroidRuntime( 5149):	at dalvik.system.DexPathList.makeDexElements(DexPathList.java:230)
E/AndroidRuntime( 5149):	at dalvik.system.DexPathList.<init>(DexPathList.java:112)
E/AndroidRuntime( 5149):	at dalvik.system.BaseDexClassLoader.<init>(BaseDexClassLoader.java:48)
E/AndroidRuntime( 5149):	at dalvik.system.PathClassLoader.<init>(PathClassLoader.java:65)
E/AndroidRuntime( 5149):	at android.app.ApplicationLoaders.getClassLoader(ApplicationLoaders.java:57)
E/AndroidRuntime( 5149):	at android.app.LoadedApk.getClassLoader(LoadedApk.java:326)
E/AndroidRuntime( 5149):	at android.app.LoadedApk.makeApplication(LoadedApk.java:508)
E/AndroidRuntime( 5149):	... 9 more
E/AndroidRuntime( 5149):	Suppressed: java.lang.ClassNotFoundException: com.android.email.EmailApplication
E/AndroidRuntime( 5149):	at java.lang.Class.classForName(Native Method)
E/AndroidRuntime( 5149):	at java.lang.BootClassLoader.findClass(ClassLoader.java:781)
E/AndroidRuntime( 5149):	at java.lang.BootClassLoader.loadClass(ClassLoader.java:841)
E/AndroidRuntime( 5149):	at java.lang.ClassLoader.loadClass(ClassLoader.java:504)
E/AndroidRuntime( 5149):	... 12 more
E/AndroidRuntime( 5149):	Caused by: java.lang.NoClassDefFoundError: Class "Lcom/android/email/EmailApplication;" not found
E/AndroidRuntime( 5149):	... 16 more