When creating maps with relative paths, the resulting saved map's data sources display as invalid when reopened. The data source path displayed in layer properties on the data source tab contains a ~ character in the path instead of the full path name.
For example: C:\washin~1\lake.shp
Data paths will also be shortened in other parts of ArcMap. This includes when editing has started and the system prompts to select a single workspace to edit. This can also be seen when working with geoprocessing models in the model builder window.
The path to the map document file is also be shortened, and is visible in ArcMap's title bar. See the Related Information section for more details.
The map document was opened by double-clicking the map document in Windows Explorer. Names and folders are displayed with the Windows 8.3 naming convention, instead of the proper long filenames.
For example, a map saved with the name MapDocument.mxd displays as 'MAPDOC~1.MXD' on the ArcMap title bar.