I was wonder ing if anyone could help me. I got the error message Error: Object not found: polyTexturePlacementPanel1 when trying to open my uv texture editor. Its annoying because its models for my 3rd year film that i am already behind on and if i have to redo them i think i may throw up.
make sure you don't have any old custom mel scripts that add functionality to the uv texture editor. I remember having this trouble because of an old mel script I had from highend3d.com that added functionality to the uv texture editor. The underlying structure of the window changed in later versions of maya which rendered the script obsolete and caused errors similar to yours.
What you could try doing is open the uv texture editor using the panels menu in a 3d viewport instead of opening it from the main Window menu. I remember that being a workaround until I found the script that was screwing everything up.