If the part is interferring with another part sometimes the decal won't display.
Make sure textures is turned on in the Environment settings.
Make sure the jpeg file is loaded on the part not the assy or sub assy. When you bring the part into the assembly locate the part to where you want it then go into Color & Appearance select Components from the down arrow, Select the component with the jpeg, Select Done Sel, click on UnSet.
This will cancel out and colors that may have been applied to the part in assembly mode.
HTH
Brian
Make sure textures is turned on in the Environment settings.
Make sure the jpeg file is loaded on the part not the assy or sub assy. When you bring the part into the assembly locate the part to where you want it then go into Color & Appearance select Components from the down arrow, Select the component with the jpeg, Select Done Sel, click on UnSet.
This will cancel out and colors that may have been applied to the part in assembly mode.
HTH
Brian