VLOOKUP Excel returns #N/A for my boss, but not for me

Question

I got tasked to take over some statistics for management at my company. These statistics are placed on a server that anyone from management has access to and me. We are generating a monthly report based on other reports that are placed on the same server.

Here come the problem: The values are generated automatically based on a VLOOKUP formula, which is just checking if the data from the other files have a certain value. When you open the report, you get a prompt if you want to update the external links. For me, no matter what I pick, I get no #N/A values. However, when my boss tries to open the same report, no matter what he picks(either update links or not), he always gets #N/A on the cells.

Because of the contract that I signed, I cannot show you any code, however, I can tell you what I have tried:

• At first, I thought that my boss has lost (somehow) some permissions with the external files. But this is not the case, we tested every file and he can access all of them, even being marked as an administrator in some cases.
• Secondly, I checked the report from the current month with one from two months ago (which works for him, no #N/A here) and went through all of the formulas. No luck here either, all the formulas are all the same except the external file name which was changing (I have done this step with the help of Spreadsheet Compare).
• Third, I thought that maybe some macro would be running in the background (even if that makes no sense because these are .xlsx files). No luck here either, there is no VBA code written in any of the sheets of the workbook.

I got no ideas left. He has all the permissions, even more than I do, there is no difference between an old report which works just fine, and this one that is stuck, and there are no running macros. Any ideas?

Edit: I can give you a sample of the formula, but will replace the actual path with a fake one since I cannot show this proper code:

=VLOOKUP(look_up_value, 'O:\fakepath\[file.xlsx]Report'!$C:$AZ, MATCH('Lookup Data'!$B$3, 'O:\fakepath\[file2.xlsx]Report'!$5:$5, 0) - 2, FALSE)

Also, I might also add details that were asked below here:

• The language settings and DateTime format is the same both me and my boss
• Both excel files have the same version, including the same display language
• The mapping of the external files is the same for both of us, since they are on a server and we both have the drive letter for the server "O"

Answer 1

No definitive answer since question does not have enough details nor sample formulas, but some ideas:

• are the 2 client machines with the same language settings (windows regional settings) ? that may impact dates and other factors
• are the versions of Excel identical ? (including language)
• external data: if here are external links, do the 2 client machines have the same drive mapping ? (could be P: on yours and R: at your boss pc)
• EDIT: same rights to source folder ?