Same happened with me, but with vim (I know emacs org mode is epic, but too much for me), I moved a quite large markdown file (I have even disk catalogues from .. ancient years) to a lot of platforms : SQLite, treeline, treeview, cherryTree plus more I don't remember now.. back to vim (with some Plugins like tablemode and folds) after all, it's a text file anyway that can be opened with any darn platform out there..