We have found 1 possible solutions to your problem.
Before you start this troubleshooting guide you need to check one important thing:
Does your tablet ring when there's an incoming call?
Yes
No
Why do we ask this question?
It's important first to find out if your tablet rings when there's an incoming call. If your tablet doesn't ring when there's an incoming call, you need to solve this problem. By solving this problem you'll most likely solve your problem with no message tone.