Why Can T I Install My Large Apk File In Android S System App Folder

I have a problem making my APK files Android system apps, which normally involves moving the APK to /system/app and changing its permission to 644.

I have done that lots of time before but this time one of my application is 69MB and , although moved successfully, it cannot be opened properly. It opens but gives an error due to lack of files I think. Settings>Applications shows the size of application is 48KB. Yes, that’s not typo! Here’s a screenshot:

Is there an apk size limit on Android that can be installed on /system/app directory?

PS: my /system dir is 1GB /cache is 500MB ram is 1GB /data is 2,5GB and application works fine on /data

thanks,

Abbas