Category contains invalid characters
Webmaster site form rejected the category (webmaster-site-input) because it contains disallowed characters or looks like a URL/script.
Why this happens
Category should be a short label (letters, numbers, spaces, basic punctuation). Values with <>, javascript:, data:, or http(s):// are blocked. Distinct from Category is too long.
Diagnose and fix
1. Use a plain category name (e.g. “Games”, “Tech”) without URLs or HTML.
2. Remove special symbols outside the allowed set; save again.
3. Leave category empty if optional and you only need the site URL.
4. See Webmaster sites and verification.