Quartus won't let me use Signal Tap. Can't elaborate "sld_hub:auto_hub"

This is very strange. Comparing side-by-side the messages you got against what I got when the design compiled successfully, the main issue seems to be the synthesis of alt_sld_fab, which is an encrypted IP used to connect Signal Tap to the JTAG. So normally, I would recommend reinstalling everything, blah, blah, blah but you've already tried that and it still didn't work.

What is the directory path to where this project is located? If it's really long, try shortening the path and removing any spaces that may be in it. Longshot: also check write permissions just in case. Maybe something in the OS is preventing reading or writing of the IP files.

I noticed that your .stp file is located in the output_files directory for some reason. I doubt that's the issue since it compiled fine for me, but try bringing it up one level to the project directory.

Try these things and report back. This is really strange.

#iwork4intel