Adding a hyperlink to some XY data source or route event layers will result in the link not being saved and the hyperlink tool will not work.
Manual hyperlinks are not supported by layers based on non-OID tables (tables without an FID or OID field). While ArcMap will let you add a link to features in these layers, the links will not be saved.
Affected layers include XY data source layers and route event layers based on:
¤ Text (.txt) files
¤ OLE DB tables (external database)
¤ Non-registered tables in a Geodatabase (includes Access and SDE type Geodatabases)
¤ SDE 3 tables