Last update by me on this thread.
I deleted all program files and data files and re-installed them.
Re-applied the patch for the InnovaDB compression bug.
The DB I dropped all tables but left the empty DB in place, as that part was working in the original install attempt.
Second time was the charm - web UI install completed without further incident, moodle installed and working now.
No idea what was causing the original error. Some file must have gotten corrupted somewhere somehow in the git/download etc., to be spitting out those stray '==' chars that triggered the above errors.
I deleted all program files and data files and re-installed them.
Re-applied the patch for the InnovaDB compression bug.
The DB I dropped all tables but left the empty DB in place, as that part was working in the original install attempt.
Second time was the charm - web UI install completed without further incident, moodle installed and working now.
No idea what was causing the original error. Some file must have gotten corrupted somewhere somehow in the git/download etc., to be spitting out those stray '==' chars that triggered the above errors.