Clicking the Details button shows the additional error information:

Also, if the user tries to Archive an Email using the “Store In Vault” EV toolbar icon from a client workstation itwill generate the following Error:
An error occurred while processing the selected item.
Clicking the Details button shows the added error information.
Error Description:
0x800706BA : The RPC server is unavailable.
Verify DCOM is Enabled on the Client Machine.
1. Go to Start / Run then execute “dcomcnfg” .
2. Expand “Console Root” à “Component Services” à “Computers”.
3. Right Click on “My Computer” and Select “Properties”.
4. Select “Default Properties” Tab.
5. Verify the Check Mark in front of option “Enable Distributed COM on this computer” is selected.
Enable the Permission to “Everyone” in “Access Permissions” and “Launch and Activation Permissions”.
1. Go to Start / Run then execute “dcomcnfg” .
2. Expand “Console Root” à “Component Services” à “Computers”.
3. Right Click on “My Computer” and Select “Properties”.
4. Select “COM Security” Tab.
5. Click on “Edit Limits” under the “Access Permissions” .
6. Select the “Everyone” and set the permissions to Allow on all options.
8. Click on “Edit Limits” under the “Launch and Activation Permissions”
9. Select the “Everyone” and set the permissions to Allow on all options .
11. Then Close Outlook and Reopen it.
12. Then try to “Restore” or “Archive” the Email once again
Also, if the user tries to Archive an Email using the “Store In Vault” EV toolbar icon from a client workstation itwill generate the following Error:
An error occurred while processing the selected item.
Clicking the Details button shows the added error information.
Error Description:
0x800706BA : The RPC server is unavailable.