VLookup Formula Error

I have a file with multiple worksheets and I need to do vlookup of UPCs from 1 worksheet called 0723 and if it is null value then vlookup from another worksheet called productmaster. The formula I came up with is

=IFERROR(VLOOKUP(UPCLookup!A2,'0723'!$B$2:$Y$63014,23,FALSE),IFERROR(VLOOKUP(UPCLookup!ProductMaster!B2:S149824,18,false),””)))

This returns an unspecified error and higlights the B2 after productmaster!
What is wrong with my formula?

Please help I am pulling my hair out.