I have iOS 10.3.3 (14G60) and Word 2.6 (171004)
I think something went wrong with this last version of Word or the one before this one more than with iOS: after the last few updates I could not print as a PDF without having some custom fonts changed into some equivalent
fonts. I experienced this with various fonts especially with Adventure which was installed via Anyfonts and it is displayed correctly but when I print it or save it as a PDF file, so that can be printed exactly as I see it in word, the PDF is displayed and
printed as if those fonts are not recognised.
Later....
By updating to iOS 11.0.3 to see if I could solve it, I made it worse. Now I also experience the same error message of insufficient memory and I can't use word anymore! I deleted and reinstalled those fonts (profiles)
but Word can be launched and after a few minutes I get that error message, then it doesn't open anymore.
As far as I remember until not long ago I was able to do everything correctly, at least until September then I think I received one or two Word updates and not it does not work anymore....