Dan has two separate phones, an LG G3 and an HTC One on T-Mobile, with two separate SIMs ( a micro and a nano), and two separate lines. He can't figure out how to send multi media text messages in Google Voice. Leo says that Google just recently decided to support MMS, but it may have not happened yet and Verizon doesn't support it. T-Mobile does though, and Dan uses both.
Leo says that Google doesn't want him to use the Google Voice App anymore. They are pushing people toward using the Hangouts app. That should solve the problem. He can make calls from Hangouts, so that could be a nail in the coffin for Google Voice.