The program does not allow me to enter a subcontractor cost on the T2125 under line 8360. How can I enter an amount
The most common reason for that space on the T2125 being greyed out is that the incorrect T2125 has been selected.
CRA has 3 different versions of the T2125 - Professional, Commission, and Business. If you have chosen the Professional (T2125 - P), the option to include anything related to cost of goods sold/gross profit is not available.
If you do have these expenses, you can clear and close that T2125 and use the T2125 - B instead.
To clear and close
While the form is open on your screen, click the Edit button in the upper right and choose Forms - clear current form.
Click Yes to confirm.
Click the Edit button again. Choose Forms - close unused forms.
You can then select the proper T2125 option for your business.