Can't set background image for android

Question

I have a problem for set an image in background. I use background tag but there is an error I don't understand! see below pictures.

Answer 1

Sometimes resources get out of sync with the file system. Do a refresh (select project in resource explorer and press F5).

Answer 2

Use the following tips.

1. Resize the background image in to a smaller resolution and size.

2. Use only *.PNG images.