"Unfortunately, SmartcardManager has stopped"
What is this error for?
I had same issue when I updated the 'Smartcard Manager' with Aptoid app. For me, I simply removed the update from Application Manager. Since then, this annoying message was gone.
If you find this particular system app never updated, you could do 'Disable' this app from /Application Manager/More/Show System Apps, or freeze it if you're using 'Titanium Backup' app until someone shows how to resolve it.
In fact, having thought of this app as one of bloating apps, I had deleted this system app for a few days for a test, but haven't found any specific malfunction. However, I restored this app now back to system because I'm still not sure what this app does for.