I have a series of documents that are all linked to a master document. I've tried to add a new document from one of our suppliers and for some reason it won't let me link it. I'm using a product code as the unique reference to match each row. I'm using vlookup function to bring the information in.

I've tried changing the format of the cell with no use, the only way I've found so far is to copy the product code from a working document into the cell, yet the formatting of said cell doesn't appear to be any different to the rest of the cells.

Can anyone tell me if it needs to be formatted in a specific way or if there is something I can do to make the link work?

Thanks.