If you've been tinkering around with the wonderful Advanced PDF/HTML Template within NetSuite there are times when you'll receive some ambiguous errors.
I received one today which had me scratching my head for quite some time, it was:
Problem saving template: Index: 2, Size: 2
-NetSuite Advanced Template error
Whenever you encounter this error it's trying to tell you there's an error in your table structure with the number of rows and cells - this will need fixing otherwise it will not save your template.