Brand new to WordPress, fallen at the first fence...
Trying to customise TwentyTwelve theme with a header image
I am not using a plugin, have just uploaded an image (with FileZilla) to wp-admin/images and it is also in wp-content/uploads/2013/01
From the Media file I try to Set as Header, but the next screen is just blank, though the menu is still visible on the left so I can go elsewhere. No image appears on my site.
I have tried as many different ways of doing this as I can think of, and at one point I got an error message: Warning: illegal string offset 'width' in xxx/xxx/xxx etc - can't remember exactly the file path, but it ended at the image name.
The image (jpg) is already at the recommended size and is less than 8mb.
Anyone got any idea what to try next?
I did manage to change the background, that went smoothly.