I have the desktop version (home & office for mac) and just got my MD forms filed after an hour of trying. I went to the forms button on the top left and then clicked errors. Alternately I also found it by scrolling down once I clicked the "open form" button at the top. I couldn't' right (or left) click but I highlighted the offending zero and then using the edit button at the top of the program I was able to find the "override" command and delete the zero. That allowed me to file my MD return (I'd already filed my federal return). I hope this helps someone! While I put in my calendar to file my MD return on the 10th, that doesn't mean I'd have actually done it!
