first touchstone. i wrote it in google doc. downloading it as .docx isnt working?

Okay, sophia learning wants a microsoft word docx format. i went to download to download as docx. my pc downloads it, but when i try and submit the file it says error. So i tried opening the file before hand, and it opens up notepad/wordpad and its all asiic or whatever. so I went to microsoft word and copy pasted the whole dang thing, and tried downloading it there. couldnt find a download button anywhere. i have no idea what to do. why is my file turning to crap when i download it as .docx via google doc? what do i do?