Erase 2018 MacBook Pro & Reset to Factory Settings

That error usually has something to do with your Internet connection. You need to be using a fast Wi-Fi or an Ethernet connection. Otherwise, the connection may time out. This is especially true for slow Wi-Fi connections.

Do you happen to know if the Recovery HD is still on the disk and working? Test for it by trying to start up from it:

Boot from the Recovery HD

1. Restart the computer.
2. Immediately after the chime press and hold down the "COMMAND" and "R" keys together.
3. Release the keys when the Apple logo and progress bar appear.
4. Upon completion, the Utility Menu should appear.

If this works, then continue.

Install El Capitan or Later from Scratch

1. Select Disk Utility from the Utility Menu and click on Continue button.
2. When Disk Utility loads select the volume (indented entry, usually Macintosh HD) from the Device list.
3. Click on the Erase icon in Disk Utility's main window. A panel will drop down.
4. Set the Format type to APFS (SSDs only) or Mac OS Extended (Journaled.)
5. Click on the Apply button, then wait for the Done button to activate and click on it.
6. Quit Disk Utility and return to the Utility Menu.
7. Select Install OS X and click on the Continue button.

This will install the version of OS X you had installed.

Internet/Network Recovery of El Capitan or Later on a Clean Disk

1. Restart the computer. Immediately after the chime hold down the (Command-Option-Shift-R) keys until a globe appears.
2. The Utility Menu will appear in from 5-20 minutes. Be patient.
3. Select Disk Utility and click on the Continue button.
4. When Disk Utility loads select the drive (usually, the out-dented entry) from the side list.
5. Click on the Erase tab in Disk Utility's main window. A panel will drop down.
6. Set the partition scheme to GUID.
7. Set the Format type to APFS (SSDs only) or Mac OS Extended (Journaled.)
8. Click on the Apply button, then click on the Done button when it activates.
9. Quit Disk Utility and return to the Utility Menu.
10. Select Reinstall OS X and click on the Continue button.

Note:

1. To install the version of OS X that was currently installed use Command-Option-R.

2. To install the original factory version when the computer was new use Command-Option-Shift-R.