Android 6.
Go to Settings -> Notifications -> Sound. Select an other than default. Some of them crash the application, and it will crash again when you go to Notifications menu. No sound plays upon notifications when any other than default is selected.
Which phone are you using?
Blackview BV6000
I managed to fix that by moving the ringtone file in /system/media and setting correct permissions. It's either matter of path or permissions. But when a file is on internal storage or sd card, you cannot set permissions. It's 660 in storage and 644 in System.
Ah, just noticed your response. Seems as it may have been a permission issue
When trying to use a ringtone file from your internal storage in other apps, what happens?
Other apps work fine, that's the point
Most helpful comment
Other apps work fine, that's the point