A warning message is returned when attempting to save a map document in ArcMap

Description

In some instances, when attempting to save an ArcMap project, the following message is returned:

Error:   
ArcMap is unable to save the map document due to the file being held open by the operating system. To resolve, please retry your save operation or use Save As to save to a different file name.

Cause

This issue may occur due to the following reasons:

• When the machine is in sleep mode due to the default sleep settings of the machine, ArcMap may stop all connections. The map remains open when the user logs in again, but ArcMap treats it as a new opening of the same map, which prevents the map from being saved. Refer to Microsoft: Shut down, sleep, or hibernate your PC for more information on Microsoft Windows sleep settings.
• The storage capacity of the machine where the map document is saved is full. This is known behavior. Sufficient storage is needed to save an ArcMap map document. Refer to Problem: Saving a map template returns the error: Unable to save. Check to make sure you have write access to the specified file for more information.

Solution or Workaround

Depending on the cause, use one of the workarounds below to address the issue.

Change the machine's sleep settings

Note:
The machine must be restarted before and after completing the workflow for the changes to take effect.

Note:
For Windows 10, refer to Microsoft: How to adjust power and sleep settings for more information on changing the sleep settings.

1. Click the Windows icon on the bottom-left of the machine's screen.
2. Click Control Panel.

 

3. Click Hardware and Sound.

 

4. Click Change when the computer sleeps under Power Options.

5. Change the Turn off the display: and Put the computer to sleep: settings, and click Save changes.

Note:
Esri recommends selecting 'Never' for the Put the computer to sleep: settings.

Offline storage capacity is full

• Increase the offline storage. Refer to ArcGIS Desktop: Hardware requirements for more information on hardware storage space for ArcMap.
• Use the Save As option to save the ArcMap project with a different filename in a different storage space.

Note:
If the problem persists, work with the organization's IT department as this involves the operating system.