Attribute redefined
The same attribute appears twice on one element.
The message, as the validator reports it
Attribute id redefined
Why it happens
- A duplicated attribute after a merge or copy and paste.
- Code that adds an attribute without checking whether it is already set.
How to fix it
Keep one of them. If both values matter, they belong in different attributes or in child elements.
Example
Reports the error
<item id="1" id="2"/>
Fixed
<item id="1"/>