Texture editor won't let me export images.

Question

Hello, these last few days I was remaking a mod of textures of sonic 06 for sadx (which by the way is someone else's, which I don't remember his name, but he spoke in Spanish and English like me), and well I wanted to export the textures of the title screen of the "AVA_TITLE_CMN_HD.pvmx" file of the mod "HD_DCStyle" but I don't know why , but when I want to export the background textures (that is the clouds that appear behind sonic), I get a window that says "generic error in GDI+". Is there a solution to this?