What it means:

“#NAME!” tells you that Excel was trying to use a “Named Range” in a formula, but that name does not exist.

Typical causes:

Named Ranges are an important tool for building models that are easier to understand and less error prone. Excel lets us assign a name to a cell or range of cells to make it easier for humans to understand what is going on. For example a formula calculating revenues that is “= unit_price * quantity_sold” makes much more sense to us than “=Sheet1!$C$4*Sheet7!$D$17”.

If a formula is referring to a named range that doesn’t exist then #NAME! will be displayed. This may be caused by an edit / typo in the formula, or if the cell or range of cells that had the name assigned have been deleted.

How to fix it:

In our models we create named ranges for the outputs of every block of calculations. This helps avoid errors where a formula could point at the wrong row, since if the name is used, then the result must correspond to that name. Deleting cells may have removed a named range and this may cause the error.

If a recent action caused the problem, use “Undo” to reverse it (Ctrl + Z or Cmd + Z).