I have had some major issues with Google Assignments lately. Some students try to open up the Google Assignment and it says, "We have trouble opening the document. Try again by reloading the page." What's weird about that is my earlier class (linked to the same class) was able to open the document just fine.
The previous day students got an error message saying, "We couldn't load your document because there is a problem with your instructor's account. Please ask your instructor to reconnect their account to Schoology." From there I went into my Google account and removed Schoology as a third-party app and then reinstalled it, but I guess that didn't solve the problem.