NetBookIt works OK until you try to make a booking, when you get an error message such as this:

 "record not found: (5) Error 0: from key BOO:ID_k "

but BookIt is fine for booking the same item

Certain characters are illegal in category and resource names in NetBookIt because they have alternative meanings to the browsers or otherwise confuse it.

Do not use ~ or # or & or \ in item names. There are probably others characters as well.

For example a resource named KW&L Yr 7 Set #2 is wrong in two ways, the & and the #.
Change to KWL Yr 7 Set 2 or similar.

If it works in BookIt, but not in NetBookIt this will be the issue.