The “Find and Replace” feature, when attempting to find and replace a New Line character, behaves unexpectedly in two ways:
Firstly, with a new line character selected like this:
(Done by holding my mouse at the end of a line, and dragging it down to the very beginning of the next time)
If you tried to open the Find and Replace menu with Ctrl+H with this character selected, the resulting window will show 0 results regardless of the number of new line characters present in the script.
Secondly, if you were to copy that new line character and then paste it into the Find field yourself, it will then correctly display all matches in that script - However, any attempt to replace these results with anything will result in a non-action when the replace key is pressed. Pressing the Replace key with a New Line character selected as a match will produce no result, regardless of what is in the Replace field.