[General Questions and Answers] Raijin:
Stock factory image of Android 4.2.1 in my Galaxy Nexus.

Apktool 1.5.1 with framework of 4.2.1 loaded.

I'm trying to recompile my SystemUI.apk. Succesfully decompiled and compiled immediately without any modification.

Adb logcat of the apk newly compiled, completely unsigned:

I/PackageManager(31359): /system/app/SystemUI.apk changed; collecting certs
E/PackageParser(31359): Package com.android.systemui has no certificates at entry AndroidManifest.xml; ignoring!
W/PackageManager(31359): Failed verifying certificates for package:com.android.systemui

Signed with signapk.jar. The logcat of the signed file, both with platform and testkey. First appears in the log the first quote, and then the second.

W/PackageManager( 428): Not granting permission android.permission.ACCESS_ALL_EXTERNAL_STORAGE to package com.android.systemui (protectionLevel=2 flags=0x83e0d)
W/PackageManager( 428): Not granting permission android.permission.INJECT_EVENTS to package com.android.systemui (protectionLevel=2 flags=0x83e0d)
W/PackageManager( 428): Not granting permission android.permission.STATUS_BAR_SERVICE to package com.android.systemui (protectionLevel=2 flags=0x83e0d)
W/PackageManager( 428): Not granting permission android.permission.REMOTE_AUDIO_PLAYBACK to package com.android.systemui (protectionLevel=2 flags=0x83e0d)
W/PackageManager( 428): Not granting permission android.permission.CONFIGURE_WIFI_DISPLAY to package com.android.systemui (protectionLevel=2 flags=0x83e0d)
W/PackageManager( 428): Not granting permission android.permission.MANAGE_NETWORK_POLICY to package com.android.systemui (protectionLevel=2 flags=0x83e0d)
W/PackageManager( 428): Not granting permission android.permission.DEVICE_POWER to package com.android.systemui (protectionLevel=2 flags=0x83e0d)
W/PackageManager( 428): Not granting permission android.permission.GET_DETAILED_TASKS to package com.android.systemui (protectionLevel=2 flags=0x83e0d)
W/PackageManager( 428): Not granting permission android.permission.REMOVE_TASKS to package com.android.systemui (protectionLevel=2 flags=0x83e0d)
W/PackageManager( 428): Not granting permission android.permission.SET_SCREEN_COMPATIBILITY to package com.android.systemui (protectionLevel=2 flags=0x83e0d)
W/PackageManager( 428): Not granting permission android.permission.START_ANY_ACTIVITY to package com.android.systemui (protectionLevel=2 flags=0x83e0d)
W/PackageManager( 428): Not granting permission android.permission.INTERACT_ACROSS_USERS_FULL to package com.android.systemui (protectionLevel=2 flags=0x83e0d)
W/PackageManager( 428): Not granting permission android.permission.INTERNAL_SYSTEM_WINDOW to package com.android.systemui (protectionLevel=2 flags=0x83e0d)
W/PackageManager( 428): Not granting permission android.permission.MANAGE_APP_TOKENS to package com.android.systemui (protectionLevel=2 flags=0x83e0d)
W/PackageManager( 428): Not granting permission android.permission.SET_ORIENTATION to package com.android.systemui (protectionLevel=2 flags=0x83e0d)
W/PackageManager( 428): Not granting permission android.permission.READ_DREAM_STATE to package com.android.systemui (protectionLevel=2 flags=0x83e0d)
W/PackageManager( 428): Not granting permission android.permission.WRITE_DREAM_STATE to package com.android.systemui (protectionLevel=2 flags=0x83e0d)

E/AndroidRuntime( 517): FATAL EXCEPTION: main
E/AndroidRuntime( 517): java.lang.RuntimeException: Unable to create service com.android.systemui.SystemUIService: java.lang.SecurityException: Call from user 0 as user -2 without permission INTERACT_ACROSS_USERS or INTERACT_ACROSS_USERS_FULL not allowed.
E/AndroidRuntime( 517):	at android.app.ActivityThread.handleCreateService(ActivityThread.java:2539)
E/AndroidRuntime( 517):	at android.app.ActivityThread.access$1600(ActivityThread.java:141)
E/AndroidRuntime( 517):	at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1316)
E/AndroidRuntime( 517):	at android.os.Handler.dispatchMessage(Handler.java:99)
E/AndroidRuntime( 517):	at android.os.Looper.loop(Looper.java:137)
E/AndroidRuntime( 517):	at android.app.ActivityThread.main(ActivityThread.java:5039)
E/AndroidRuntime( 517):	at java.lang.reflect.Method.invokeNative(Native Method)
E/AndroidRuntime( 517):	at java.lang.reflect.Method.invoke(Method.java:511)
E/AndroidRuntime( 517):	at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
E/AndroidRuntime( 517):	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
E/AndroidRuntime( 517):	at dalvik.system.NativeStart.main(Native Method)
E/AndroidRuntime( 517): Caused by: java.lang.SecurityException: Call from user 0 as user -2 without permission INTERACT_ACROSS_USERS or INTERACT_ACROSS_USERS_FULL not allowed.
E/AndroidRuntime( 517):	at android.os.Parcel.readException(Parcel.java:1425)
E/AndroidRuntime( 517):	at android.os.Parcel.readException(Parcel.java:1379)
E/AndroidRuntime( 517):	at android.view.accessibility.IAccessibilityManager$Stub$Proxy.addClient(IAccessibilityManager.java:203)
E/AndroidRuntime( 517):	at android.view.accessibility.AccessibilityManager.<init>(AccessibilityManager.java:200)
E/AndroidRuntime( 517):	at android.view.accessibility.AccessibilityManager.createSingletonInstance(AccessibilityManager.java:182)
E/AndroidRuntime( 517):	at android.view.accessibility.AccessibilityManager.createAsSharedAcrossUsers(AccessibilityManager.java:153)
E/AndroidRuntime( 517):	at com.android.systemui.SystemUIService.onCreate(SystemUIService.java:73)
E/AndroidRuntime( 517):	at android.app.ActivityThread.handleCreateService(ActivityThread.java:2529)
E/AndroidRuntime( 517):	... 10 more

Any idea about how to resolve this problem? Thank you!