Apple numbers loan calculator on iPad stopped calculating showing error

The error is "this formula can't reference its own cell or depend on another formula that references this cell". It obviously is not referencing itself so it is something to do with A, F, or H. Column H has an error also so maybe it is referencing column G. What is the formula in column H? Are A and F manually entered numbers or are either a formula?

The latest upgrade and the @ symbols shouldn't have created a circular reference where there had not been one, but it is difficult to say what is going on from what you have posted do far.

I am thinking this is a bug in how it "upgrades" the old formulas. Cell C19 formula is referencing cell I18. Cell I18 is referencing C18 and G18 (and not C19) but the range C18:C377 includes C19 and it looks like it is considering that to be a circular reference after the "upgrade".

If I change all those references from the form @A$18:A377 to just plain @A (and similar for the others), I think the problem goes away. Or you might consider changing them to single cell references so that @A$18:A$377 would simply be "A19" in cell C19's formula, and similar changes in the other formulas. There is no need for using range references the way this table does.

I would also consider moving away from the Excel paradigm of one large table that contains everything. Row 1 can be replaced with a text box. Rows 2-15 should be a separate table. Rows 17-377 would become the main table. The chart will sit on a clear spot on the sheet, not on top of a table.