Google HTML5 Validator - Missing primary asset check
A banner I've uploaded has come up with the error [Missing primary asset check].
On Google Ads Help, it mentions this [Primary .HTML files include an Ad Size tag such as <meta name=”ad.size” content=”width=300,height=250”>.]
I've added it, but still doesn't pass the validator.
Can anyone advise on a fix please?
Many thank.
