To ensure that the builder is set onto the project, open the Properties dialog for the project and go to the Validation property page.
If the Add Validation Builder to project checkbox is present, enable it.
Then, enable the Build checkbox for the desired validators, overriding the main validation preferences if necessary. Further information explaining the cause of the validation error will appear in the Problems view.
Selecting the error in the Problems view and either double-clicking on it or choosing Go To from its context menu will highlight the error in the Source view allowing users to quickly locate and correct the problem.
To open the Problems view, select Problems from the menu bar (Window -- To run validation as part of building, the Validation Builder must be set on the project and the desired validators enabled.The XML editor will process XML files that are invalid or not well-formed.The editor uses heuristics to open a file using the best interpretation of the tagging that it can.Validation errors are shown as blue wavy underlines. It contains a reference to an XSD file, which you will also need to copy from below or download and enter into the webpage (in a second step, when you are prompted for it) to see the validation results.It is designed to accommodate a large number of users, ranging from beginners to XML experts.