I have installed Australia-complete-photoreal-xp11zip and have encountered the below problem with the Sydney HD folder.
Upon XP11 start up I reveive the following message, afterwhich, XP11 shuts down.
Cannot trace Sydney HD/terrain/ 78720_20528_NSW_C 17_ter
Cannot trace Sydney HD/terrain/..textures/78720_20528_NSW_C 17.dds
I had to place the Ortho_Australia Sydney HD folder into the Scenery disabled folder to enable Xplane to properly boot up.
If there's an answer to this Ortho_Australia Sydney HD 'missing files' prob, I'd like to hear from you.