I had this happen earlier this week. The fix that worked was a Admin > Repair > Quick Rebuild, then going into the .htaccess at [root]/public/legacy and making sure RewriteBase was set to /public/legacy.
I had this happen earlier this week. The fix that worked was a Admin > Repair > Quick Rebuild, then going into the .htaccess at [root]/public/legacy and making sure RewriteBase was set to /public/legacy.