While trying to customize the New/Edit/Display forms in a custom list using SharePoint designer, you may encounter any of the following errors
- This form was customized not working with attachment
- An unexpected error has occurred.
- Can’t move focus to the control because it is invisible, not enabled, or of a type that does not accept the focus.
The solution for each of the above issue is given in the below support document.
Some times while solving one error you will end up with the other one. So follow the step provided for the new error you face.