I tried loading a file with a texture larger than that set up to the scene background, and I soon as I went into the Materials tab with that selected, I got that warning. The HDRI's preview looks like a plain color in P12. Been using these in P11 for years.

- - - - - - 

Feel free to call me Ohki!

Poser Pro 11, Poser 12 and Poser 13, Windows 10, Superfly junkie. My units are milimeters.

Persephone (the computer): AMD Ryzen 9 5900x, RTX 3070 GPU, 96gb ram.