An attribute value specification must be an attribute value literal unless SHORTTAG YES is specified
I have encountered this problem with W3C validator, which you may have too.
In my situation, the error came from putting html code
<img alt="" />
It can happen with padding css code as well, the error message will be “an attribute value specification must be an attribute value literal unless SHORTTAG YES is specified” (see image).
I try as i can, to clean up and validate my blog’s code, this is why some small things like this i have to fix.
To fix it, add ” or ” for the width, height, or padding, depends on your source code.
My code was like this;
The fix was like this.
After you correct the code, you can then “revalidate” your document again.