Failed to start the Unity Package Manager local server process with any errors

Unity Engine
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1

Hello everyone. I’m trying to launch Unity 2021.3.45f1, but the loading stops at the “Starting Server” stage, and then returns the error “Failed to start the Unity Package Manager local server process. Make sure the process [D:/UnityEditor/2021.3.45f1/Editor/Data/Resources/PackageManager/Server/UnityPackageManager.exe] is not blocked by Windows Defender or any other anti-virus configuration.” My antivirus definitely does not block any files. I’ve read a lot of different forums about this error, but not a single method has helped me. When I try to run UnityPackageManager.exe through CMD, I get this error: "OpenSSL configuration error:
13156:error:0200107B:system library:fopen:no protocol option:C:\build\output\unity\upm\build\node\16.20.2\deps\openssl\openssl\crypto\bio\bss_file.c:69:fopen(‘C:\xampp\php\extras\ssl\openssl.cnf;E:\xampp\php\extras\ssl\openssl.cnf’,‘rb’)
13156:error:2006D002:BIO routines:BIO_new_file:system lib:C:\build\output\unity\upm\build\node\16.20.2\deps\openssl\openssl\crypto\bio\bss_file.c:78:
13156:error:0E078002:configuration file routines:def_load:system lib:C:\build\output\unity\upm\build\node\16.20.2\deps\openssl\openssl\crypto\conf\conf_def.c:170:"But the problem is that I don’t have a folder on my computer C:\build\ and all that, and the E disk is not involved in Unity at all. When trying to boot on other versions of Unity, the same thing happens. If anything, I communicate through a translator, so there may be errors in the text.

When I click on diagnose, I get this:

image
image1850×515 39.2 KB

I will also attach the diagnostic log:

Unity Package Manager Diagnostics (v0.2.0)

Ran 6 checks

5 succeeded
1 failed

:white_check_mark: UPM registry reachable (PASS)
Make an HTTP request to the UPM package registry

HTTP/1.1 200 OK
X-Powered-By: Express
Date: Fri, 25 Apr 2025 18:03:19 GMT
Via: 1.1 google
Transfer-Encoding: chunked
Alt-Svc: h3=“:443”; ma=2592000,h3-29=“:443”; ma=2592000
Connection: close

:white_check_mark: Ping UPM registry (PASS)
Measure the latency of the UPM package registry API

17 pings made in 5.23 seconds
Average latency: 31.57 ms
Minimum latency: 26.70 ms
Maximum latency: 38.02 ms
Standard deviation: 3.15

:white_check_mark: Ping UPM download (PASS)
Measure the latency of the UPM package download endpoint

12 pings made in 5.29 seconds
Average latency: 36.77 ms
Minimum latency: 33.82 ms
Maximum latency: 39.73 ms
Standard deviation: 1.87

:white_check_mark: UPM registry download speed (PASS)
Test the Internet connection using the UPM package registry

Measured speed to the UPM registry: 79.89 Megabits per second

:white_check_mark: HTTP proxy environment variables (PASS)
Detect whether proxy-related environment variables are set (HTTP_PROXY, HTTPS_PROXY, ALL_PROXY, NO_PROXY, UNITY_PROXYSERVER, UNITY_NOPROXY)

No proxy support has been configured through environment variables.

:cross_mark: UPM health check (FAIL)
Start the UPM process and call its health endpoint

Server exited unexpectedly. Exit code: 123

Please, help

2

How do you know? You can only be sure of that by adding your project folder and unity installs to the antivirus exclusion list (for live/online scans).

The antivirus may have also considered some essential files as “dangerous” and already removed those, leaving a broken install. It’s worth a try to disable antivirus and uninstall, then re-install the editor version.

For the record, what antivirus? There are some known to be really pesky little annoyances. And generally speaking, 3rd party antivirus are all but useless, they do not offer worthwhile security enhancements over Windows Defender for average users.

Because you installed the editor to a non-default location D:/UnityEditor/ you may be running into issues due to that. Depending on who created that folder under which account / privileges. If you manually create a new folder on D: and it prompts you to “allow making changes” you can be certain the permissions on that drive are incorrect, possibly it was formatted on another system / previous OS install.

Try installing Unity to its default location to check if that fixes it and if so, note the permissions on that folder under program files, then uninstall and reinstall to the custom location and apply the same permissions to that folder.

Oh and whatever you do, do NOT run Unity installer, the Hub, or the Editor as “administrator”.

Those paths refer to paths in the build system the editor was built with. They are not paths on your system but the Unity team’s build machine. So just ignore those.