longer sequences with lots of graphics or effects.
i'm getting out of memory errors a bit working with XDCam footage with lots of subtitles.
we've also got A+B cameras displaying side by side.
sometime a 3rd camera which is a different codec (Prores)
if i keep too many sequences open i get problems, so i close them down.
closing the canvas altogether helps for a while,
but eventually a re-start is required
lots of markers might add to the problem, not sure,
but extended markers will drastically slow you down when zoomed in
"it has been around 170-200mb for quite awhile and worked fine, only recently did it start crashing"
are you keeping older versions of edits in your project?
most of them can be put into another project
nick