XML Online Viewer
Open the viewer
XML validation errors explained
Validators phrase the same rule differently: libxml2 (used by Python's lxml, PHP, xmllint and this site) says This element is not expected, Java's Xerces says cvc-complex-type.2.4.a: Invalid content was found. Each page below covers one rule with both wordings, typical causes, an example and the fix.
| Error | Xerces code |
|---|---|
| This element is not expected | cvc-complex-type.2.4.a |
| Missing child element(s) | cvc-complex-type.2.4.b |
| Not a valid value of the atomic type | cvc-datatype-valid.1.2.1 |
| The value is not accepted by the pattern | cvc-pattern-valid |
| The value is not an element of the set | cvc-enumeration-valid |
| Value too long or too short | cvc-maxLength-valid |
| Value greater or less than allowed | cvc-maxInclusive-valid |
| More digits than allowed | cvc-totalDigits-valid |
| The attribute is required but missing | cvc-complex-type.4 |
| The attribute is not allowed | cvc-complex-type.3.2.2 |
| Character content is not allowed | cvc-complex-type.2.3 |
| No matching global declaration for the validation root | cvc-elt.1.a |
| Duplicate key or missing key reference | cvc-identity-constraint.4.2.2 |