What does the error “ETM?” mean when I swipe a credit card? Posted on December 6, 2016December 11, 2018 by Bulldog Tech This error is a connectivity issue, so you should check your internet connection first. Other factors that could cause this are ip address problems or if you renamed the computer hosting the database. Post navigationPrevious post: How do I use the “Global Menu Item Price Change” feature?Next post: I get an error 3251 in aldelo how do i fix it.