Can't send texts -- "Invalid Number"

I am unable to send text messages to a friend because Cricket immediately bounces back a text saying that the number is invalid, which it is not.  This has happened with 1-2 other numbers, but the majority of numbers work fine with no issues.  I have tried various Google solutions, to include checking my APN settings, clearing my visual voicemail cache, and clearing my Messages cache and data, but nothing has worked so far.  The only other theory seems to involve a bad SIM card from switching networks, however this SIM card is from our original Cricket phones, so that should not be an issue.  How can I resolve this kick back to be able to send messages to these numbers?