Transactions repeatedly failing

[john-light]

Have had about a dozen users in the past couple of weeks complain about transactions failing when converting in both directions. I wrote up some documentation about how to interact directly with the contracts to complete the conversion but this should be the exception rather than a common occurrence.

[sohkai]

We may want to link to the self-help instructions during the openBuy/SellOrder() step.

At the moment, it is unclear why users are not progressing to the last step (claim order), but we will also add analytics to analyze how prevalent this issue is.