AttValue: " or ' expected
An attribute value is not in quotes.
The message, as the validator reports it
AttValue: " or ' expected
Why it happens
- Unquoted values, allowed in HTML but not in XML:
qty=2. - Curly “smart” quotes pasted from a word processor instead of straight ones.
How to fix it
Put every attribute value in straight double or single quotes. The two follow-up messages, attributes construct error and Couldn't find end of Start Tag, come from the same mistake and go away with it.
Example
Reports the error
<item qty=2/>
Fixed
<item qty="2"/>