I think the problem is when reading in your conditions file - it seems to think that there’s 16 rows when there’s only 1, but the last 15 are all blank (hence the AttributeError - it’s expecting a filename and trying to access the attributes of a string, but it’s getting None).
As a quick fix, go to your loop and delete the contents of the Conditions field. Then click the Open In Excel button to make a new Excel file and paste the contents (as “Text Only”) of the old practice.xlsx file into it, then save over practice.xlsx. As a more long term solution, I’ll look into why the read function is no longer filtering out blank rows.