Try to send pic in Hangouts and get the message shown in the title.
What account are they referencing and where are the settings to change the account to accept photos?
Photos send fine to the same contact if I change to SMS.
Yes, I have 2 accounts. How do I change the account I'm logged in to? How do I know which account I'm logged in to? I can send and receive email from either account without logging in - I just select which address I want to use
Go to the main Hangouts screen (where you can see all of the threads), and look at the name and account at the top. That's the currently active account. To switch accounts, swipe in from the left--you should see all of the available accounts there. Tap on the one you want to use.