What I am trying to do is fetch a single list item that has the highest ID, but also has a value in the Shelf field. Below is my query, which I am pretty sure I formatted correctly.
<View> <Query> <Where> <IsNotNull> <Field RefName='Shelf'/> </IsNotNull> </Where> <OrderBy> <FieldRef Name='ID' Ascending='False' /> </OrderBy> </Query> <RowLimit>1</RowLimit> </View>
However, when I test the code I get the error
Request failed. One or more field types are not installed properly. Go to the list settings page to delete these fields.
I am not sure what it is that is going wrong, since I checked that I am using the actual column name, not the display name (which are the same in this case anyway).