In command line, for a single file, you can use: xmllint --noout your-file.xml. This command displays nothing if your file is OK. Else it indicates where the error is. This command is for quickly sorting an xml file out; it can miss or may not find some errors.

(The Kate editor has an option (a plug-in) to validate the active xml file.)

Else just run: make validate-en. You must get a “No error” message.

Else, a list of validity errors is displayed with line numbers referring to the en.xml log file that you can find in the /log folder.

Open this en.xml file in a text editor, type the editor “jump to line” command (the Kate editor command is Ctrl+G) and enter the line number to jump to the concerned line in the en.xml file. There, you will find the error.

If you have worked on several XML files, look above in the en.xml file to find (in the “xml:base” field of the “id” tag), in which xml file the error is.

Fix the error. Don't forget to save the file and run make validate-en again.

	Bemærk
	A frequent foolish mistake is editing the en.xml log file instead of the XML file.