I opened the sample company fine.  The sample company was set to use single UOM.  I tried to import my data and it said I needed a UOM set.

I dont use UOM, because I can't.  I can not use UOMs in the Pro edition.

I verified and rebuilt my data as you instructed, with no errors found.

I can not turn on UOM to import my items because it is not available in the Pro edition.

This seems like a bug to me.  You should still be able to import Inventory Parts even though you do not (cannot) use the UOM option.  It did allow me to import my non-inventory parts fine.  But once I specify a COGS, or Income account it pops up the error about the UOM being turned off.