When a student clicks on a Google Workflow assignment either nothing happens or they receive the error below. This usually happens because the browser they are using is blocking 3rd party cookies. See below for the steps to allow cookies.
Click on the 3 Dots in the upper-right corner. Then click Settings.
Click on Security and Privacy.
Click on Cookies and Other Site Data.
Make sure Allow All Cookies is selected.
Now students should be able to open the assignment.