I'm having a strange problem with my Samsung S4 using the stock, current firmware. The phone is new and straight out of the box. Updates have been allowed to proceed and now report current.
Google+ reports 'Data connection error'. This error should not be taken literally as there is very clearly a fast network connection available: on both 4G and wifi. Every other network accessing app, including other Google apps (including those using the Google user account) work fine.
I've cleared the app cache and data without effect. The issue existed prior to and after a Google+ app update.