[Phssthpok]

The best thing to do is to undo the change on the file you show, and do "Find" to see what gets highlighted before you hit "Replace". I suspect that you should use "dot-all" instead of "(.|\n)", and use a much more specific regex (e.g. look specifically for "<img"). I've often tripped up with things like "<.*?>x" when I wanted a tag followed by x, and it matched "<...>...<...>x" instead -- but changing it to "<[^>]*>x" worked fine.