Is this a daycare?  If not, did you accidentally fill it out in the daycare section, rather than on Line 1 and 2?

been there, done that  LOL

I accidently filled out the day care sec. Thanks!

You probably were doing the simple $5 per sq ft method.  further down the 8829 under the traditional method you will find the lines for sq ft of office (again) and for total house.  Enter there and it will populate the note on Sch C and allow efile.   [There should have been a warning when we run diagnostics, but...]