Thank you for your reply! I tried renaming the .scribus directory, but it doesn't rebuild the directory. Reinstalling Scribus doesn't change anything either (and it still doesn't rebuild the .scribus directory).
My system is a simple five year old desktop (Intel i3-6100, Nvidia GTX 1050, 8GB ram, sata SSD). It has been running the same installation of Arch Linux for five years, which is up to date (Linux kernel 5.14.14-arch1-1). I have used Scribus on this system frequently, but last used it this summer, so I don't know precisely when it began crashing. I have not noticed any other indications of SSD failure and just ran a S.M.A.R.T. test on the drive, which it passed without errors.