Bill,
Did you try the tips here in #4?
https://www.smartsheet.com/blog/support-tip-how-to-print-gantt
Tim
Hi Bill, it sounds like you may have accidentally added an incorrect date on one of your rows. Go through your sheet and check your dates to find the date. I would zoom all the way out of your Gantt chart and scroll through to see if you can identify the incorrect date.