In the Info module you can check, among other things, whether the references / links on the pages are valid and work. Invalid links can occur if

• the internal page that is linked to has been deleted
• the file, which is linked, was deleted
• an external link has been misspelled (e.g. goggle.comm instead of google.com)

Select the Info module in the Link validation view. In the Report tab, you will see the result of the last validation. If you have never performed the validation, a green bar is displayed - but this does not necessarily represent the actual state of your page. To update the report, switch to the Check Links tab and check all 3 boxes.

You can specify the levels in which the links are checked (Check these levels). To check all pages at once, select the Pages element in the page tree and Infinite for the levels. However, only the pages will be checked. Quick Links etc. must be checked additionally.

Then select the Check Links button. Now switch back to the Report tab. The result of the check will be displayed here. If invalid links are found, they will be displayed in a list (see image).

Now you have to solve the shown problems manually. You can recreate the report as often as you like to check whether the references have been changed correctly.