I added 'autocmd BufEnter * syntax sync minlines=4000' to my .vimrc to make it buffer more of large files initially, so it gets less confused when you reopen a

I added 'autocmd BufEnter * syntax sync minlines=4000' to my .vimrc to make it buffer more of large files initially, so it gets less confused when you reopen a file and it resumes at a prior location deep inside and has no syntax highlighting. I guess fromstart would work as well, but is probably best manually run like you do so a very large file doesn't bring the system to a halt.