67428: Acronis Cyber Protect, Acronis Cyber Backup: Agent registration fails with "503 service unavailable" if http_proxy environment variable exists

use Google Translate

Last update: 17-09-2021


  1. You want to install an agent in an environment with a proxy.
  2. You have configured proxy according to the user guide (Acronis Cyber Protect 15
  3. Agent registration fails with the following error:

    503 service unavailable


The issue is most commonly caused by the presence of http_proxy environment variable: Acronis services attempt to use this "proxy" for local connection.

To confirm that issue is caused by this environment variable:

  1. Open Command prompt: Start -> in Search, type cmd.exe and press Enter.
  2. Issue the following command: 


  3. If the output of the command contains "http_proxy" parameter, then this is the cause of the issue

This issue will be fixed in future versions of the product.


Acronis Cyber Protect 15: this issue has been fixed in Build 26172, please update to the latest build.

Acronis Cyber Backup 12.5: use the workaround below:

Remove http_proxy variable: e.g. run the following command from Command Prompt:

setx http_proxy ""

Reboot the machine.

More information

If there is no http_proxy environment variable in the list, then the issue is not covered in this article and needs investigation. Contact Acronis Support with a reference to this article.