os.h | A simple context switcher for Cortex-M0 processors

It seems that your HomeFragment doesn't have no parameters constructor. If you want to use fragment that requires constructor parameters you need to provide FragmentFactory to navigation component.

Add empty constructor HomeFragment() to HomeFragment, and it should work.

As it was described in the reference:

When creating the NavHostFragment using FragmentContainerView or if manually adding the NavHostFragment to your activity via a FragmentTransaction, attempting to retrieve the NavController in onCreate() of an Activity via Navigation.findNavController(Activity, @IdRes int) will fail. You should retrieve the NavController directly from the NavHostFragment instead.

Looks like you should use

Issues

You have a UNIQUE index on the NUM_JUG column (perhaps implicit if NON_JUG is defined with PRIMARY KEY) and you are using the standard update method which uses the default conflict action of ABORT and therefore fails if an attempt is made to duplicate a NOM_JUG value.

As secondary issue is that the SQLiteDatabase update method returns the number of updates (see extract and link below) (same for updateWithOnConflict). The number returned will never be -1 it will be 0 or more (0 indicating that no updates have been applied).

As per SQLite Database - Update

Returns

int the number of rows affected

Fix

To fix the main issue you should use the updateWithOnConflict method. This takes a 4th parameter a conflict and you probably want IGNORE so you could use :-

This line:

I think, the problem is here. String.valueOf(R.string.channel_name) just gives a string containing the integer ID. As a result, due to unknown/unregistered channel, you got bad notification error. Hence, use the actual String.

As per the documentation on launch():

This method throws ActivityNotFoundException if there was no Activity found to run the given Intent.

While any of the ActivityResultContracts (such as the GetContent one you're using) should be available on every device, users may be running a custom build of Android that removes the apps / system utilities that handle these common intents or the user may have manually disabled the app (this is more common with things like a Browser or Camera app than this particular case).

Therefore you should consider surrounding your call to launch() with a try/catch block that catches an ActivityNotFoundException and informs the user that their device does not support this functionality.

This is because you are not initializing the variables but creating new ones on onCreate() whose scope is inside onCreate().

Hence, the variables you declared outside onCreate() are always null and you get the exception.

Make these changes in your onCreate() method code and it will work fine

It turns out that the ViewPager wasn't the issue. The transition will only work if there is an equal amount of views in the layouts we are transitioning to/from. Adding empty views inside the CardView in Fragment A resolved my issue: