Last night AD went to year 2000. Linux clients joined to AD freaked out right away with scary security warnings. A reboot fixed them right away after AD time was set right. Or setting time manually.

Windows had authentication trouble so Shares, Printers, etc stop working for clients. For some reason I had to rebooting them many times fixed them, no idea why one wasn't enough. Had trouble reported all today even though it was only off for 2 hours last night.

Hard to believe Windows doesn't do sanity checking on this stuff.

Engrade is not open source. The OP asked specifically for open source. That said Engrade is a fine program and has a API that could easily integrate with a open source school information system, I speak from experience doing this myself.

It's a fair point that they keep a few things closed source - in particular the ability to host multiple schools in one instance. Their install requires basic knowledge of ruby and git which would rightly frighten some people off.

I still think it's a good contender and is for the most part open source. I would agree Moodle can do more, but I think Canvas can do what it does better and is vastly easier to use.

Are you looking for a school information system (SIS) to store all teacher grades and print reports? Or a gradebook for individual assignments?

I made a SIS in django https://github.com/burke-software/django-sis that would let you make spreadsheet templates (with the teachers students already in) for teachers to enter grades and then upload them to submit their grades. It has a very customizable report builder for report cards that lets you edit the template in Libreoffice and throw in some variables and other magic (for student in students: do this).

For a gradebook I'd suggest Canvas. Moodle is an option, but IMO their gradebook is not very good. Canvas can't do school wide report cards by itself but has a nice API for integrating it.