I am trying to use a simple vlookup formula in excel and it is not working. Not sure why.

=IF(VLOOKUP($B2,Sheet2!$A:$AX,26)="","","X")

Basically if the result is blank I want a blank. If the result has a date or text then I want the result to be an X not the actual value (date or text).

I have tried several different versions and nothing is working properly. It is a simple formula so not sure why none of them are working properly.

I have also tried:
=IF($B2="","",IF(ISBLANK(VLOOKUP($B2,Sheet2!$A:$GF ,26,FALSE)),"","X"))
=IF(ISERROR(VLOOKUP($B2,Sheet2!$A:$AX,26,FALSE))," ","X")

Thank you for your help.