I can't start my MacBook Air mid 2014, when I want to reinstall macOS it says that the recovery server could not be contacted. I have already erased the disk with disk utility. What can I do?
You must format the internal drive again before you can install the OS. Use Disk Utility for that.
Use Mac OS Extended (Journaled) format and the GUID partition scheme. Name the drive Macintosh HD.
Erase and reformat a storage device in Disk Utility on Mac - Apple Support
Make sure that once you launch Disk Utility, you select View > Show all Devices. Then select the top-most drive selection available in the side bar and click Erase.
You must format the internal drive again before you can install the OS. Use Disk Utility for that.
Use Mac OS Extended (Journaled) format and the GUID partition scheme. Name the drive Macintosh HD.
Erase and reformat a storage device in Disk Utility on Mac - Apple Support
Make sure that once you launch Disk Utility, you select View > Show all Devices. Then select the top-most drive selection available in the side bar and click Erase.
This is a common problem when trying to reinstall High Sierra in recovery.
The fix for "Recovery server cannot be contacted" can be found here: https://mrmacintosh.com/how-to-fix-the-recovery-server-could-not-be-contacted-error-high-sierra-recovery-is-still-online-but-broken/
Look at Fix #3.
I tried, but it doesn't work.
Now it's working, but I can't choose the disk to install macOS on.
Since you've already erased the Mac, then your best option may be to find another Mac that is capable of running the High Sierra OS and use that to create a bootable USB installer for this Mac.
Create a bootable installer for macOS - Apple Support
The 2014 MacBook Air can run macOS up to Big Sur, so you could download High Sierra, Mojave, Catalina or Big Sur. Frankly, unless you have some reason for sticking with High Sierra, I'd install the newest OS the computer can run; Big Sur.
Can’t start macbook air 2014. Recovery server could not be contacted
