Pre-defined metadata missing

I am in the trial phase of DEVONthink and playing around with it. I looked at Custom metadata and there was a list of Pre-defined items so I picked “Price” as I will be entering receipts and bills which have a dollar amount. I also added a brand new Custom Metadata field called “Payment Type” so I could specify if it was paid by bank card, credit card, direct debit etc. When I look at Settings/Data now the list of pre-defined terms is missing. I investigated and found if you clicked the down arrow next to the circle with dots in it you were supposed to be able to “Add default templates” but it is greyed out. How do I get the pre-defined items back?

It’s only available if at least one of the default templates is missing. A screenshot would be useful.

Price and Date are the only pre-defined fields I selected. I am sure there was a list of pre-defined items before I got to the list as it is showing in the screenshot. It included items like Date Added, Date Modified and a lot of other items I can’t remember.

All pre-defined fields seem to be available but most of them are not enabled. Date Added/Modified can be e.g. found in the Info > General inspector, not in Info > Custom (at least not without setting this up on your own).