Depending on the type of bill you are testing you will see HCFA like output on a blank page for HCFA bills, you will see many lines of somewhat garbled text and information if you are testing an X12 claim. That garbled text is the X12 EDI 4010A format. Occasionally you will see odd characters that look like dominoes or squiglies, these are control characters such as page feeds and are normal.