LAG/LEAD 'Offset Amount' should allow line item inputs when the data type is not a number

When using the formula LAG/LEAD(Value to offset, Offset amount, Substitute value) in the classic engine, if 'Value to offset' and 'Substitute value' are not numeric, you will receive the following error if the 'Offset amount' is a line item reference

The 'value' argument for the 'LEAD' function should have datatype of NUMBER not BOOLEAN:

LEAD(value:NUMBER, offset:NUMBER, fill:NUMBER, [mode:?])

Use a direct numeric value as the second argument in the formula rather than a number-formatted line item

OR 

Use the OFFSET function instead. OFFSET works the same as non-strict LEAD, and you should make sure the second argument is a negative value if you want to simulate the LAG function.