My final grade/class average column says "No Grade" after completely revising my categories (and, yes, I re-selected the new categories).

I ran into the same thing. I split my Lab category into Lab-Document and Lab-Questions, splitting the weight percentage. I changed the [[Code]] in classroom to reflect, and the Categories under the Settings Tab to all match [[LabDoc, 100]] and [[LabQs, 25]]. I did an Import and they matched in the colums LabDoc and 100 Weight, etc. However, the Grade column say "No Grade" for every student, yet each assignment has a score and percentage score for every student for every assignment. So the raw scores are there, the over all average is not being determined. I did not disturb any other columns so not sure what happened. I even made a Copy of the class and resetup a the Classroom and did an Import but it is the same. I shared the file with Tony and you all. Hoping to know what the fix is.

Thanks!

This is usually happens if the Gradebook has been modified. Try to revert to the latest stable version of your Spreadsheet and perform import again to sync it with the Classroom. Thanks.