Rhys,
Are you looking at the FORM in design view or the TABLE in design view?
Please post
-a jpg/png of your table designs
and
-any form designs with properties showing.
Rhys,
You want to bring up the properties for the TABLE in design view.
The FORM binds a control to the table, so you can think of it as a "Window" to the field in the table. We still need to know what the TABLE is doing.
Think of it this way, if the TABLE says "This is a number", but you have a text box on a form that is trying to put "One hundred" into the number, the TABLE will complain about it, since you are trying to put text into a number.
If you can see the FORM, can you bring of the FORM's properties while in design view? If so, you can see, on the "Data" tab, the "Record Source. This should point to either the TABLE or the QUERY.
If it is a query, you would need to look for that query to see what table(s) it is pulling from, and from there identify which table you need to look at.
You want Form's properties. You are showing a control's properties.
In form design, right click on the little black square at upper left of form, select form properties.
Click the DATA tab and show us the recordsource for the form
OK so the Kits table is the table that underlies the inventory modification form That is the table involved.