I think I figured it out. It has something to do with the length of the classroom name. For example, my classrooms with longer names wouldn't work. When I shortened the name, it did. it didn't like: BW B9 - Main Class/Reading, but liked BW B9 Reading.
Out of my 5 classrooms with the same students (I have them separated by subject because of the 150 assignment limitation), 3 of them worked, but 2 of them consistently comes up with the null error when I try to import students.
I'm getting that same error from one of my classrooms: Something went wrong: Cannot call method "getRange" of null.
One worked, but that one won't. Trying the others now. Same students in both.
Can you please share the "Google Classroom Information" document with me ( firstname.lastname@example.org )?
Still the same I'm afraid! :-(
This is odd. On your screenshot you have a link for a document "Google Classroom Information". Can you delete this document and try one more time? You can find the document here: My Drive -> Grade Reports for Google Classroom. I apologize for the inconvenience
Just tried it on 0.51. Still get this...
We have released an update that should fix your issue. Please check that you have the latest version (0.51) and try it again. Let me know if the issue still occurs.