When you open a map using arc map you may see a besides lay

When you open a map using arc map you may see a \'!\' besides layers. Why and how do you fix?

Solution

In arc gis, when you open a map and u see \'!\' beside layers name, that shows that for that layer the link to its data source is broken and hence it wont be displaying the layer on the screen.

To fix it, select the layer, go to its properties, go to source tab, and select/click on set data source. This will let you to select the data source for the layer, doing so will remove the mark if the data source is working.

well, You can also click the red exclamation mark to open the Set Data Source dialog box.

Hope this is what you are asking. Good Day!