Here are the errors which have been found in the printed version of Cracking the Cryptic's Greatest Hits. All mistakes have been fixed for the latest version of the PDF.
On a number of pages, the URL doesn't match the page number. Each QR code and URL leads to the puzzle it's beside.
The 0's are one cell too short. Here's what it should look like:
The rules mistakenly read "N may be any number". There is no "N" in this puzzle, so that sentence can be ignored.
The top left cage on page 67 is wrong. It currently looks like a long Z, but it should curve differently. It should look like this:
There is a 4 in row 2, column 6 that should not be there. There should also be a "U" in row 3, column 7.
There's a small typo in the text: the "12" in the example should be "21".
The cage starting in row 3, column 3 is one cell too tall. It should end in row 5, column 3, like so:
The circle in row 4, column 2 is missing. Again, this is correct in the online version of the puzzle. It should look like this:
There's a missing digit in the grid; row 2 column 9 should be a 9, as so:
One of the yellow stars in the final puzzle of the Harry Potter hunt needs to be moved one space to the left. It should look like this:
The top left section is missing a cage. The two L-shaped cages in the top-right box should be mirrored. Here's what it should look like:
The bookmark puzzles were inadvertently printed without given digits, making them unsolvable. Here's what they should look like:
Additionally, the rules state that each row, column, and 4x4 box must contain the digits 1-16. "Row" shouldn't be included: only each column and 4x4 box need to contain the digits 1-16. The two sides of the bookmark are separate, and do not interact in any way.