With frng
..Formula =
"=TEXT(VLOOKUP(CONCATENATE(""00"",B4),'[ZRMA.xls]Format'!$A$2:$P$" &
Workbooks("ZRMA").Sheets("Format").Range("A65536") .End(xlUp).Row &
",16,0),""0000000000"")"
End With

Hello. I worte an add-in for everyone in the company to use. 99% of the
people that try it say it works perfectly. There are a few people that say
it errors out on their machines. I went to one of them, and the above line
of code is where it errors, specifically the piece of code:
Workbooks("ZRMA").Sheets("Format").Range("A65536") .End(xlUp).Row

If I replace that with a simple Range("A4:A1000") it works. Any idea why
this doesn't work on some machines? Thanks!