You are getting the error:
"HP:MSL G3 Series" could not be opened("Device could not be accessed")
and then,
"Starting the device path discovery process"
Did DP find a new device file, then start using it? If so, this is normal DP behavior when teh device file on the Exchanger or the Drive has changed. The device file changing is an OS issue, meaning that it is not the same as when you originally configured it. This can happen if you are in a SAN environment
If you are in a SAN environment, I suggest that you enable Persistent Binding on your Network Switch Router (NSR) so that device addresses do not change when a system is rebooted