Note by @fastfinge

@dandylover1 "Text files used by Notepad should be no larger than 45K. Notepad cannot open a file that exceeds 54 kilobytes (K) in size and does not allow you to continue editing a file if the file size reaches between 45K and 54K." from an Archived version of the Microsoft Support website in 2017: web.archive.org/web/20170828143936/https://support.microsoft.com/en-us/help/59578/maximum-file-size-limits-for-notepad