Attempting to download the HD textures just closes the game and brings up the launcher but doesn’t open anything to do with downloading the textures. This has been persistent for me since I came back about a month ago.
EDIT:
I managed to find a workaround
go to cata on the launcher, click the gear icon next to play.
select “modify install”
in the window that pops up, click “modify install” again
check “High-Resolution Textures” and confirm.
you will now start installing 40GB of textures