About This HTML Issue
The path in an <object> element's data attribute can't contain a literal space, so write each space as %20 or rename the file so its URL has none.
The data attribute holds the URL of the resource the object embeds, often a PDF, and the URL Standard doesn't allow spaces in a path. The validator reports values like /docs/annual report.pdf, and one stray space is enough, as in /docs/fees_ 2025.pdf. Accented letters in a file name are allowed, so only the space needs fixing.
Browsers percent-encode the space when they request the file, so the embedded document usually still shows. The markup is invalid anyway, and a tool that reads the raw value may not encode it. A space after the ? gives a different message, Illegal character in query, and %20 fixes that one too.
When the object has a fallback link to the same file, the link's href gets its own Illegal character in path segment error. Change both values together.
Invalid example
<object data="/docs/annual report.pdf" type="application/pdf" width="600" height="800">
<p><a href="/docs/annual report.pdf">Download the annual report (PDF)</a></p>
</object>
Valid example: space encoded as %20
<object data="/docs/annual%20report.pdf" type="application/pdf" width="600" height="800">
<p><a href="/docs/annual%20report.pdf">Download the annual report (PDF)</a></p>
</object>
Valid example: hyphen instead of a space
<object data="/docs/annual-report.pdf" type="application/pdf" width="600" height="800">
<p><a href="/docs/annual-report.pdf">Download the annual report (PDF)</a></p>
</object>
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