Index/ Match - error on letter characters

I'm having an issue matching the reference to the array. The reference is multiple letters and I believe that is what is causing the issue. B7 is where the output is.

You aren't comparing similar start points for your matches.
i.e.
Sheet3!B2:D112 row 2
Sheet3!A:A row 1

Try in B7

=INDEX(Sheet3!B1:D112,MATCH(Sheet1!D2,Sheet3!A:A,0),MATCH(Sheet1!B4,Sheet3!B1:D1))

Or

=INDEX(Sheet3!B2:D112,MATCH(Sheet1!D2,Sheet3!A2:A112,0),MATCH(Sheet1!B4,Sheet3!B1:D1))

Hope this helps