please send an image of Format property of the form's date field that is not working.

Double check that the field type in the underlying table is Date/Time.

Yes, they are both set to Date/Time. I've also tried adding in the default =Date() in each of the table field properties as well, to no effect.

Add a date format for example yyyy-mm-dd in the first property 'Format' as in the image above.
And try it again.

Add a date format for the text box. This should force the Date Picker to show.

What's the recordsource? Table or query?

Hi guys. Thanks for the suggestions - adding the date format to the form properties worked. The date picker shows fine now. Strangely though FYI I've had to remove the vba that called the Date Picker - that still throws out the vba error. Richard, the form creates the start and end date (as per your video - 'Between Dates') which are then stored in a table, which is then called by a query. The form is therefore, I guess, based on a table.
I have a supplemental quick question for you please - another field on the form just requires the input of a year - usually the current one. It's easy to input the year but how do I populate the field with the current year automatically allowing for it to be changed if necessary.
Again, thanks for the solution to the Date Picker problem.
Regards. Bob.

I answered my own supplemental question -  =DatePart('yyyy',Date())

Yep - and put that in the Default Value field so the user can change it.

You could also use =Year(Date())