Not sure there's a hidden file, but there's one that, when present, is automatically loaded: "preferredState.pz3". Delete it to retrieve Poser 11's default scene.
Look here: "Macintosh > Users > your_user > Library > Application Support > Poser Pro > 11

You may arrive here using the finder's menu "Go to" (I think) while pressing the Option key

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👿 Win11 on i9-13900K@5GHz, 64GB, RoG Strix B760F Gaming, Asus Tuf Gaming RTX 4070 OC Edition, 1+2 TB SSD's, 6+4TB HD
👿 Mac Mini M2, Tahoe 26.5, 16GB, 500GB SSD
👿 Nas 10TB
👿 Poser 13 and 14 ❤️

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