How do I use a VLOOKUP array from Another Workbook?

From the VLOOKUP fx dialog box, I click the shrink button for array, switch to file containing the array, then select the array. Result inserted in the array box looks like:

This results in a function error. Result in dialog box is #REF!. If I enter the function, cell shows Err:504.

How do I fix the array reference?

Why don’t you show the full VLOOKUP() formula you are using (#REF! (error 524) and Err:504 are incomprehensible different - watched from a distance)

(btw: The name of your table is really DNm?)

Full VLOOKUP formula:

Formula is in a file in the same directory.

LibreOffice Version: (x64)
Build ID: 639b8ac485750d5696d7590a72ef1b496725cfb5
CPU threads: 8; OS: Windows 10.0 Build 19041; UI render: GL; VCL: win;
Locale: en-US (en_US); UI-Language: en-US
Calc: threaded

Why is worksheet name DNm objectionable?

Why is worksheet name DNm objectionable?

Not at all - just to be sure that mixture of upper- and lowercase isn’t a typo. Tried exactly your formula and it works for me.