ConvertA1FormulaToR1C1 throws an exception whenever it is passed a formula or string that contains a range name "Listx" where x is any integer. The exception is "Invalid Column Expression". To reproduce the problem, try this:
CellsHelper.ConvertA1FormulaToR1C1("=1+List2", 1, 1)
compared to this:
CellsHelper.ConvertA1FormulaToR1C1("=1+ListA", 1, 1)
It doesn't seem to matter whether Listx is a valid name or not, or what range it refers to. It also doesn't matter whether the formula is passed as a string or as the formula property of a cell.