When users attempt to checkout of the NetCommunity estore using the options for creating a new user or using an existing user; clicking continue after entering the username and/or password may result in a message declaring the username is already in use.
This issue was resolved in the latest versions of Blackbaud NetCommunity and eStore.
Steps to Duplicate
go to estore front page while not logged in
add and item to the estore cart
proceed to checkout
Select option for I am a new user
fill out shipping info and select option for this is same as billing info
enter credit card information
enter password and confirm password
notice form does not proceed
click continue again
receive message This User ID has already been used
From step 4 select radio button for I am an existing user