How do I solve "Signature mismatch", when building my own system app. - Android Q&A, Help & Troubleshooting

I am trying to make a modified /system/app/NfcNci.apk , but when I load it on the device, I get the below error. What do I have to do to build to fix this? This is on a rooted stock Nexus 4. I built apk using standard google source, and pushed file over using adb. Thanks.
Code:
W/PackageManager( 529): Signature mismatch for shared user : SharedUserSetting{4182adf0 android.uid.nfc/1027}
E/PackageManager( 529): Package com.android.nfc has no signatures that match those in shared user android.uid.nfc; ignoring!

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CptanPanic said:
I am trying to make a modified /system/app/NfcNci.apk , but when I load it on the device, I get the below error. What do I have to do to build to fix this? This is on a rooted stock Nexus 4. I built apk using standard google source, and pushed file over using adb. Thanks.
Code:
W/PackageManager( 529): Signature mismatch for shared user : SharedUserSetting{4182adf0 android.uid.nfc/1027}
E/PackageManager( 529): Package com.android.nfc has no signatures that match those in shared user android.uid.nfc; ignoring!
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This thing comes when the target device contains apk/dex(odex) file with a different signature, which is normaly due to the fact that the app is build by some others, or some other adk. Or any other adk other than yours( i mean the one u used to create ur modified apk).
The solution goes like this,
Uninstall the apk, and remove its odex(dalvic cache ), if its a system apk, use root access to do it.
If its a critical app( which will turn of ur device if u delete it, like phone apk etc) create a recovery flashable zip of ur apk, go to recovery, wipe cache, dalvic cache, and flash ur zip.( remember to rename the apk exactly as it is in ur device, else it wont replace the original one, also set appropriate permissions). Reboot.
Dissable signature verification by patching core.jar ( lucky patcher application can do the trick for u). But its not recomended, unless u know what it is and what it can.
Sent from my HD2 using xda premium

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Thanks I ended up fixing this by just copying the AndroidManifest.xml and the INF directory from the original apk into my modified one and it worked.
showlyshah said:
This thing comes when the target device contains apk/dex(odex) file with a different signature, which is normaly due to the fact that the app is build by some others, or some other adk. Or any other adk other than yours( i mean the one u used to create ur modified apk).
The solution goes like this,
Uninstall the apk, and remove its odex(dalvic cache ), if its a system apk, use root access to do it.
If its a critical app( which will turn of ur device if u delete it, like phone apk etc) create a recovery flashable zip of ur apk, go to recovery, wipe cache, dalvic cache, and flash ur zip.( remember to rename the apk exactly as it is in ur device, else it wont replace the original one, also set appropriate permissions). Reboot.
Dissable signature verification by patching core.jar ( lucky patcher application can do the trick for u). But its not recomended, unless u know what it is and what it can.
Sent from my HD2 using xda premium
Click to expand...
Click to collapse