How to resolve "Error searching for packages : UnityEditor.EditorApplication:lnternal_CallUpdateFunctions ()"Error searching for packages Cannot perform upm operation: Unable to perform online search?

Question

Hello,
I am working on Unity3D. I get this error when I open the package manager Cannot perform upm operation: unable to verify the first certificate [NotFound] UnityEditor.EditorApplication:Internal_CallUpdateFunctions() Is there a URL I need to whitelist?

Cannot perform upm operation: Unable to perform online search:Cannot connect to 'api.unity.com' (error code: ENOTFOUND). Verify your environment firewall policies allow connection to this host name. lf your system is behind a proxy, verify your proxy environment variable.

Error searching for packages : UnityEditor.EditorApplication:lnternal_CallUpdateFunctions ()

Answer 1

TRY TO LOG-OUT AND LOG-IN IN UNITY HUB

1. The following domain names need to be accessible (whitelisted in your company firewall rules, if required) for Unity Package Manager to work:
   • packages.unity.com
   • download.packages.unity.com
   • The Unity Package Manager connects to these URLs using HTTPS by default. You can configure the proxy to use by setting the HTTP_PROXY and HTTPS_PROXY environment variables before launching Unity.
2. Can you ask your IT to also whitelist these URLs:
   • dl.bintray.com
   • api.bintray.com 
   • akamai.bintray.com
3. You have an antivirus enabled? For example
   • Norton 360 — Best Antivirus for Windows, Android & iOS
   • Bitdefender Total Security — Advanced Malware Protection With Tons of Additional Features
   • McAfee Total Protection — Best for Online Security (+ Great for Families)
   • Windows Defender.Some time to block the Package Manager.
4. Network configuration requirements for the Package Manager (firewall whitelist, proxy settings) in order to help troubleshooting network-related issues.
   1. Firewall configuration
      • The following domain names need to be accessible by the Unity Package Manager process. They are accessed using HTTPS.
        • packages.unity.com
        • download.packages.unity.com
        • dl.bintray.com
        • api.bintray.com
        • akamai.bintray.com
        • upm-cdn.unity.com
      • It may be necessary to add the above domain names to the firewall whitelist.

              2. Proxy configuration

                  When using a proxy server, you may need to configure the HTTP_PROXY and HTTPS_PROXY environment variables for the Unity Package Manager to use it when it performs requests against the Unity package registry.

             3. Setting environment variables for the Unity Hub

                  WINDOWS

                   1. Open a text editor such as the Notepad program.

                    2. Enter the following text, replacing proxy-url with your proxy server URL, and adjusting the Hub install path as needed:

                    3. Code (csharp):

                                               @echo off

                                                set HTTP_PROXY=proxy-url

                                                set HTTPS_PROXY=proxy-url

                                                start "" "C:\Program Files\Unity Hub\Unity Hub.exe"

                    4. Save the file to a location where you can easily find it (e.g. the Desktop), and make sure the file has the .cmd (e.g. launchUnityHub.cmd).

                    5. Double-click the file to launch the Hub with the environment variables set, or invoke it from the command prompt for the same effect. These environment variables will be passed on to any Unity Editor process launched                          from the Hub.

                MacOS

                1. Open a Terminal window and enter the following script after replacing proxy-url with your proxy server URL, and adjusting the Hub install path as needed:

                2. Code (csharp):

                                            echo '#!/bin/bash

                                            export HTTP_PROXY=proxy-url

                                             export HTTPS_PROXY=proxy-url

                                             nohup "/Applications/Unity Hub.app/Contents/MacOS/Unity Hub" &>/dev/null &' > launchUnityHub.commandchmod +x launchUnityHub.command

                3. This create the launchUnityHub.command file, which you can move to a convenient location (e.g. the Desktop).

                4. Double-click the file to launch the Hub with the environment variables set, or invoke it from the terminal for the same effect. These environment variables will be passed on to any Unity Editor process launched from the                            Hub.

Remarks

• If the Hub is already running, the script will just bring it into focus without relaunching it, so it will not re-apply the proxy settings if you change them. You need to shut down the Hub completely first.
• You may change the path to the Unity Editor program if you prefer to launch the Editor directly, or do not have the Hub installed.
• The double quotes around the path to the program are required if there are spaces in the path.
• (macOS only) Double-clicking the script will open a Terminal window or tab and leave it open, even after the script finishes. This can be changed in the Terminal.app preferences.

Troubleshooting

Proxy server using a self-signed certificate: There have been issues reported with using a self-signed certificate for the proxy. These certificates are considered insecure and will be rejected by the underlying HTTPS layer used by the Package Manager.

I suggest you look at this pinned forum thread: https://forum.unity.com/threads/network-configuration.590470/