getting an error when creating a dynamic named range

Hello,

Excel has been messing with me lately. I'm using the OFFSET function to create a dynamic named range. In this case, the range will expand to the height of a column.

In the Name Manager, here's what I'm entering in the 'Refers to:' box:
=OFFSET('campaigns'!$A$1,0,0,COUNTA('campaigns'!$A:$A),16)

What I'm trying to do: select all rows where A has a value (there are no empty rows), and the 16 columns to the right of and including A.

When I try to enter it, Excel says "The formula you typed contains an error."

I'm pretty confident that there is no error. In fact, I've successfully declared some named ranges in the same style. Interestingly, when I look at the references that do work, they look like this:
=OFFSET(reference!$E$2 0 0 COUNTA(reference!$E:$E) [this is copy and pasted]
=OFFSET(reference!$E$200COUNTA(reference!$E:$E)12)____ [this is how it looks in the 'refers to:' box. the underscores are spaces]

Is Excel corrupted? Has anyone experienced something like this?

Thanks for the help.

campaigns_upload.xlsx

Here it is. I'm trying to enter that same OFFSET line as a named range for this spreadsheet.

Thanks for trying it out. I think my Excel is messed up. The ABC reference is weird just like before. I think I'll reinstall Excel...