Form 7203 Line 1 is for the Stock basis beginning of the corp tax year but Check This Entry Number says Number of days you required services shouldn't be less than zero

[chris-bourne]

Check Entry makes no sense.  Stock basis is a dollar value,   or -, not a number of days.

[Rick19744]

This is a first year form and a very close form number to the form 7202.

This entry cannot be less than zero.

So if you are attempting to enter a negative number, you will get that erroneous warning.