Deductions & credits

I'm not sure you got the gist of my question, but thanks for trying.  We own a single residence, in which we live, in M county. When I was through with most of the state info, it asked about property taxes on our residence in L county.  We don't have a residence there.  I decided it meant that for that particular county, there were other taxes involved, so I just skipped it.  

Even though the software told me that I would likely be taking the standard deduction, it asked for property taxes and automobile registration info anyway.  I wish it had told me early on that I didn't need to list charitable donations to get the $300 deduction, so I did.  When it got to the review point, it said, "your charitable donations are too high."  Huh?  It took me to what looked like the paper form and showed that I could only take $300 of it.  Why didn't it figure that out and fill it in automatically?