[no voice]

In addition to doing the previously suggested measures, you should also check the physical components of your network. I had a similiar voice issue and it turns out a bad network cable was the primary cause of the problem. It affected only some internet related programs and none in the same way.

[Voice not working tried everything]

I had a similiar problem with voice suddenly not working any longer. My issue turned out to be a problem with my home network. I had to reset my router back to factory settings and I replaced a network cable that wasn't making a secure connection. Despite this being what fixed it, it wasn't affecting any other programs.

[voice is not working, I have it enabled & voice works great outside of sl...]

I had a similiar problem just recently. My issue turned out to be problems with my home netork. It took me resetting my router and replacing a network cable and now all is good.