The only way I found to work to fix the "0" entry on line 27b of your schedule C was to do as follows:
Go to TOOLS
Select TAX DATA
Find Schedule C form
Click on Line 27b
Right click on the "0"
Select "Cut" from the drop down menu thus leaving the line blank.
Save your return.
Close out Turbotax and restart.
You should now be able to run the Smart Check for your return and continue to the "File your return" option.
Worked well for me rather than following the online assistant's advice to print out form 7025 (which turbotax doesn't support) and mail my return via USPS thereby increasing the receipt of my refund by more than 3 extra weeks vs. e-filing which is supposed to be free. I don't know why Turbotax doesn't support all forms needed, especially when I bought the software because they promised to help me complete my taxes without error.
