Forms :: Error 13 When Setting Rowsource Of Combobox Using Union Query

I am trying to design an unbound combobox whose rowsource can be dynamically set based on a union query in order to search 1000's of names returning each name that contains a user defined string. The search does not start until the user defined string reaches 3 characters in length.

There are more details in the attachment but basically the vba code I used all saves OK in the vba editor but I get a runtime error 13 type mismatch when the code attempts to utilise the query to populate the rowsource of the combobox.