We reported this bug to Venmo on June 27, 2017 but Venmo hasn't been able to address it yet.
There are a few ways to work around this issue:
1. You can settle up using the Splitwise mobile app instead of our website. This bug does not affect the mobile apps.
2. If you are using a trusted computer, one thing that may fix the issue is to log in to your Venmo account using the same browser you use for Splitwise.
- Go to venmo.com in a separate tab of the same web browser.
- Log in, using the two-factor code
- Select "Remember this Device" (do not use this if on a shared device, such as a library computer).
- Re attempt the payment on Splitwise. You should be able to log in to your Venmo account via Splitwise without error.
3. As a fall-back, if you settle up on the Venmo website, you can always "record a cash payment" in Splitwise to record your payment by hand.
If you can't use method 1 or 2 above, please contact us at email@example.com for more information. Thanks!