Error Code 9.78

Does anyone know how to solve this?

I'm also having this problem.  I've reached out via in game ticket multiple times but they've given me troubleshooting links and told me to try a different network...all have not helped.  Can anyone help?  I'm trying to transfer my gmail/android game account to my Ipad using EA account transfer and it just will not work.  Tried my wifes Apple phone, her Ipad and my Ipad.  All get to the point where I can confirm the account i'm trying to transfer (level and name) but then get the error code above.

Please help - would like to play on my Ipad and buy an apple card during the promotion lol

I transferred my swgoh account from one email address to another through EA account, and when I have to confirm that my account is the one that appears linked in EA connect it gives me error 9.78.
I contacted EA support but they gave me troubleshooting links and the problem is clearly not that. This error only happens on mobile devices, since in the PC app I can log in to my account.

Thank you! I was unable to find out how to actually log out of my Google Play account, as I couldn't find an option to do so, but I did have 2 accounts, luckily one was a throw away account and deleting this account sorted the problem. 

Thanks a lot!