I press continue but it just takes me back to where I can either "fix federal return" or "file by mail". It also seems to have erased what I entered.
The error messaging you are seeing with regard to the wash sale entries is a result of automatic rounding of the number imported from your broker or typed in by you. If the wash sale adjustment is $0.49 or less, then it is automatically rounded to zero. This type of rounding is allowed by the IRS. Unfortunately, zero is not a valid value for this field -- thus the error message.
To resolve the issue, you can edit each individual transaction and delete the amount entered in the wash sale adjustment if it is $0.49 or less. This will clear the error message.
To do this, you will need to revisit the input section for the Form 1099-B transactions. Use the following steps: