More Collection Type

Can you give more information? You are logged in as a Librarian, right?
It is not possible to *delete* collection types, and you can only edit the loan period for a collection type.

Collection Types was unpopulated when I started to enter a sample book

Having misspelled book, (Bad Finger) I tried to edit it. Even though there is an edit button it would not permit me to edit.

Once you have inserted a type, you can only change its loan period. You will have to add a new type (properly spelled!). At present, there isn’t anything you can go about existing types. (Deleting and/or editing type names can cause database consistency issues, unless I go though the collection database and update things when types are edited or deleted — requires some non-trivial coding to do that properly.)

I suppose I could re-install. There’s only one book in the collection at the moment ??

Re-installing won’t fix it, unless you manually delete the database tables.