It is a known issue, see the following from TurboTax
Why am I getting the login error message, "There has been an error accessing your online session. You can "try again", but if you continue to get this message, please " exit" and log back in later"?
the link does not work.
my situation is as follows:
when i am finishing with completing the 2018 tax details i a clicking on "file" and afterwards being ask to pay for the turbotax products. since i am having a foreign address i can only pay with credit card. after typing in all the credit cards details the error message appears. this is now the 4 day in a row..
_________________________
Sorry, but US Citizens residing in foreign countries.... Must have a US credit card with a US billing address too...
https://ttlc.intuit.com/community/payments/help/can-i-pay-my-turbotax-fees-with-a-foreign-credit-or-debit-card/00/26512
____________________
Both conditions are met. There must be a different root cause.
Upon clicking on "Exit" button following message appears (this is now the 7 day in a row.):
"TurboTax Online is temporarily unavailable.
We are working to resolve the issue and apologize for the inconvenience caused by this delay. We do not currently have an estimated time when TurboTax Online will be available. Please check back later this evening"
I have the same issue. I have no idea what is causing it, but I do have a foreign filing address with US billing address. I used to have to edit the filing address, pay, then restore the filing address, but they don't say that this year.
Okay, somehow I just tried something that I did in previous years since it seems like all the messages and help are missing this year. I have a foreign filing address, so you have to temporarily update My Info with a US address, then pay with your US credit card and get all the way to just before printing, then change My Info back to the foreign address.