Hi there and welcome
Once it is connected to the phone via bluetooth, if its compatible with the phone it would just work when calling from the watch.
Whats the make and model of the phone and what happens when you try to call?
ok, thats not a error the watch would usually give and is not part of the error messages.
You get this when calling any number?
ah ok, thats the issue, it cannot be used with the Samsung, its only for the LG range of phones. Its the samsung that gives the error via this.
All watches are limited to the same model phones for communications. You have to use this with for example the LG G3, its not going to work for calling from the S6 and why it gives an illegal exception.
No problem, ill opt out and you can work with another expert.
All the best
Hello my name is***** do not rate until we are finished. I look forward to assisting and am very sorry to hear that you are having this problem. Can you tell me where you are seeing the android operating system information? I just want to double check as what Richard said is correct a lot of the time. The reason for that being proprietary software specific to the devices allowing communication to each other.