Plesk can't open Updates page with 504 error. Autoinstaller can't resolve autoinstall.plesk.com

Symptoms

• Plesk Updates page (Tools & Settings > Updates) provides error 504.

• Errors like below are provided in /var/log/plesk/install/autoinstaller3.log log:

[2024-06-29 20:19:52.085930] SourceUrl: fixed url is http://autoinstall.plesk.com/
[2024-06-29 20:19:52.086004] FileFetcher new object: target_dir=/root/parallels/, main_source_url=http://autoinstall.plesk.com/
[2024-06-29 20:19:52.086112] FileFetcher: get file (~empty)/products.inf3
[2024-06-29 20:19:52.089563] Downloading file products.inf3: 0%
[2024-06-29 20:20:32.133706] Downloading file products.inf3: Could not resolve host: autoinstall.plesk.com. Will retry in 3 second(s)...
[2024-06-29 20:20:35.134482] Downloading file products.inf3 (retry 1 of 3): 0%
[2024-06-29 20:21:15.170492] Downloading file products.inf3 (retry 1 of 3): Could not resolve host: autoinstall.plesk.com. Will retry in 7 second(s)...
[2024-06-29 20:21:22.172099] Downloading file products.inf3 (retry 2 of 3): 0%

Cause

Server is unable to resolve autoinstall.plesk.com or resolves it into incorrect IP, and therefore can't list available packages/updates.

Resolution

1. Log in to Plesk server via SSH

2. Remove custom records related to autoinstall.plesk.com from /etc/hosts

3. Check if the DNS resolvers specified in /etc/resolv.conf are responding to DNS queries, and fix the configuration if needed.