The possible causes are

• The top cover or bottom cover was opened while the machine was cooling.
• The top cover or bottom cover was opened during printing.
• Media is jammed.

Press the cut button () to cut the tape, and then remove the printed tape. Then, reinstall the paper core holder.
After printing on fabric ribbon, use scissors to cut it, and then remove the printed fabric ribbon. Then, reinstall the paper core holder.
For details on replacing the paper core holder, click here.