Although chat from Google+ was possible when logged into the account in Firefox, the account associated with the non-gmail address started life as a youtube account, hence it had never been connected to a gmail account. This seems to be a requirement, see also:
So, added a gmail account, removed it and re-established the non-gmail account as the primary login.
Can now sign in to Empathy properly.
Tested by sending an invite to a second gmail account not already displayed in the G+ chat list of online users. This worked properly and could send message back and forth as expected.
However, as yet all of the existing G+ contacts are showing as offline (which they are not - the second gmail account has a contact that is visible to both accounts and can see that contact fine).
This could be a result of the account having been messed around with, won't know for sure for a while, as it's possible any changes may take a while to propogate, just a heads up if anyone else has the same problem.
Ok, mostly sorted now, it was the account.
Although chat from Google+ was possible when logged into the account in Firefox, the account associated with the non-gmail address started life as a youtube account, hence it had never been connected to a gmail account. This seems to be a requirement, see also:
http:// support. google. com/talk/ answer/ 141360? hl=en superuser. com/questions/ 444262/ using-google- talk-with- a-non-apps- non-gmail- google- account
http://
So, added a gmail account, removed it and re-established the non-gmail account as the primary login.
Can now sign in to Empathy properly.
Tested by sending an invite to a second gmail account not already displayed in the G+ chat list of online users. This worked properly and could send message back and forth as expected.
However, as yet all of the existing G+ contacts are showing as offline (which they are not - the second gmail account has a contact that is visible to both accounts and can see that contact fine).
This could be a result of the account having been messed around with, won't know for sure for a while, as it's possible any changes may take a while to propogate, just a heads up if anyone else has the same problem.