RSS Feed XML Parsing Error

RSS Feed XML Parsing Error

Elena Rodriguez ·

Symptoms

You visit yoursite.com/feed/ and instead of clean XML, you get a wall of red text screaming about malformed content. Or worse — your email newsletter tool stops sending because it can’t parse your feed anymore. This error means something is injecting bad characters into your RSS output, and XML parsers are brutally unforgiving about that.

What Causes RSS Feed XML Parsing Error?

  1. Extra whitespace or blank lines before <?php or after ?> — This is the number one cause. A single blank line after the closing ?> in functions.php or a plugin file injects whitespace before the XML declaration, and that breaks everything.
  2. A plugin outputting HTML or notices into the feed — PHP warnings, deprecated notices, or ad-injection plugins dumping markup into the feed stream.
  3. UTF-8 BOM (Byte Order Mark) — Your text editor saved a file with an invisible BOM character. XML parsers choke on it.
  4. Special characters in post content — Unescaped ampersands, curly quotes pasted from Word, or emoji in older MySQL configurations that don’t support utf8mb4.
  5. Corrupted theme functions.php — A bad edit or failed update left the file in a broken state, throwing PHP output before WordPress can render the feed.

How to Fix It

Step 1: Confirm the Error

Open your feed directly in a browser and check what you’re dealing with.

All Error Fixes