When spray paint appears in Left 4 Dead 2 and says that the image has been damaged, it is usually caused by incorrect settings. The specific setting process is as follows:

First copy the image to be sprayed For pictures, it is best that the pixels should not be higher than 512*512. If the pixels are wrong, you can open Paint, click Image-Properties, and set it to 512*512 pixels.

Then paste the image you just copied, and then stretch the point in the small right corner of the image until the white background is just covered. Save it in JPEG format and the file name must be in English or numbers (the path must also be all in English) or numbers), open the game, import the image in multiplayer and use it.