MarsEdit 5.4.5 has been released with enhancements focused on performance, particularly improving the speed of syntax highlighting and live preview updates, along with numerous bug fixes addressing preview window flickering, text editing, publishing errors, and Tumblr-specific issues. The update also improves security handling and crash reporting, ensuring a smoother and more reliable blogging experience.
https://redsweater.com/blog/4287/marsedit-5-4-5-a-heck-of-a-lot-of-bug-fixes