Under v1.8, a written_book object requires double quotes around the text in the pages items, thus: written_book->tag->pages->"Page text"
Under v1.7, this was not present nor required.
As a result, when a 1.7 save is opened in 1.8, although the item ID is correctly migrated to the new String format, the page text becomes invalid (as it is not surrounded by double quotes) and so does not display.
Books created in 1.8 have the double quotes, and can be viewed correctly.
Suggest that either (a) requrement for double quotes be removed, or (b) migration function that changes the ID to a string also add the quotes.
Attached image shows what you see if you attempt to read a 1.7 book under 1.8
Attachments
Comments 5
I take your point about downgrading, and improvements to the data format; but in this case, shouldn't the 1.8 software modify the 'pages' tag to be compatible at the same time that it modifies the id property to the new string format, so that a world previously playing in 1.7 can be continued under 1.8? Otherwise, this will break a lot of existing worldmaps, map editors, and map generators.
Downgrading is not supported, also they changed books and signs to the new formatting (json) so its much easier for map makers/server admins to make a book without having 3rd party editors to add color text and unicode. Also its wise if you are upgrading or downgrading MC versions to make a backup before or the world(s) will not properly work.