61955: Acronis Backup: Agent registration fails with error "Could not resolve host: localhost; nodename nor servname provided, or not known" on macOS

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Operating Systems: 


1) You are trying to install, update, uninstall, register or unregister Agent for Mac.

2) Agent registration on Management Server fails with the error message:

Could not resolve host: localhost; nodename nor servname provided, or not known


3) If you run ping localhost command in Terminal, you receive the following message:

ping: cannot resolve localhost: Unknown host


There is an issue with network configuration of the Mac with Agent: string for localhost resolution is missing in the hosts file. As a result, register agent tool fails to resolve localhost during registration.


1. Open Terminal

2. You need to update the /etc/hosts file. Run the following command:

sudo nano /etc/hosts/

Specify admin password, if prompted.

3. Add the following line in the hosts file: localhost 

4. Press Ctrl+O to save changes to the file. Press Ctrl+X to exit the editor.

5. Reattempt the installation/registration.



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