Found it! C 27b answer

FINALLY!

Can't eFile due to C 27b shows "0"?    Must be blank, no 0.  Can't delete in Forms either, so:

Go to step by step, 

Business> Choose what I want to work on

Business income and expenses> update

Choose your business> edit

Business Expenses> Other common business expenses> update

Energy Efficient building>  update

here you can finally backspace or delete the "0"  This must be blank, no numbers at all or you cannot eFile