Hello,
     I am attempting to run the an update query but when I run the query I receive the following error message: "Function is not available in expressions in query experssion '(Mid([InvoiceLineDetail]![CustomerField1], 3, 3))'. I was able to sucessfully run the same query on the same database on my development machine but for some reason it will not work on my production machine.
     I have heard that the reason why an expression may not be available may be due to a reference library issue. When I look into the reference library there are several. Which one is the right one and am I on the right path?

Thanks!!!
BT