Libre office uses up too much memory

what should one turn off in libre office 6.4.7.2 so it doesn’t use up all the memory

thx

I would suggest upgrading to a more recent version of LibreOffice.

If you have good reasons for sticking with 6.4.7.2 then click Tools > Options > LibreOffice > View and untick Use OpenGL for all rendering. Click OK and allow LibreOffice to restart.

If the above does not apply to your system, then this time please add details about your system

my os forces me to use this version of libre office

thats option is not listed - see screenshot - where is it?