The main administrative account credentials for the Blackbaud Merchant Service (BBMS) may have changed but not correctly updated in the NetCommunity website.
Log into the BBMS web portal using the main administrative account credentials. Once logged in, access the user accounts area to confirm that the account you logged in with is indeed the main BBMS administrative account. Note that the main administrative account indicates that it cannot be deleted. It is this account's credentials that you must use in other Blackbaud products.
Using these credentials, log into the NetCommunity website and access the Administration,Merchant Accounts screen. Edit the Blackbaud Merchant Services account and update the username and password.