What does the F01 error message mean? My dryer just stopped and I cleaned out the duct and it still won't start again and keeps flashing that error message.

An F1 (F01) is a communication error between the control board and the EPROM on that board (the place where the program is stored). You could try to reset the unit by unplugging it for 30 seconds and plugging it back in and seeing if it will reset itself. Check with Whirlpool on a recall for this problem with this machine.