Avast Web Shield breaks Electron-based apps via ERR_CERT_AUTHORITY_INVALID on localhost

Avast Free Antivirus / Premium Security
1

I am writing to report a critical issue where the Avast Premium Security breaks all Electron-based applications (such as Bitwarden and Antigravity) on my Windows machine.

When Avast protection is active, these applications fail to launch or display a blank screen. If I disable Avast temporarily, they work perfectly.

[Error Log Example (from Antigravity app)]

[2026-05-26 21:46:46.138] [info]  [IDE Wizard] Already shown, skipping.
[2026-05-26 21:46:46.140] [info]  Starting app (v2.0.6) with dynamic port…
[2026-05-26 21:46:46.141] [info]  
Spawning: C:\Users\Sino\AppData\Local\Programs\antigravity\resources\bin\language_server.exe --standalone --override_ide_name antigravity --subclient_type hub --override_ide_version 2.0.6 --override_user_agent_name antigravity --https_server_port 0 --csrf_token 3da770a9-2a9d-4da8-8def-a95a55c19f16 --app_data_dir antigravity --api_server_url https://generativelanguage.googleapis.com --cloud_code_endpoint https://daily-cloudcode-pa.googleapis.com --enable_sidecars
[2026-05-26 21:46:46.239] [info]  [Auto-Restart] Port changed! Reloading all windows with URL: https://127.0.0.1:50935/
[2026-05-26 21:46:46.240] [info]  
============================================================
[2026-05-26 21:46:46.240] [info]    Local:       https://127.0.0.1:50935/
[2026-05-26 21:46:46.240] [info]    LS Logs:     C:\Users\Sino\AppData\Roaming\Antigravity\logs\language_server.log
[2026-05-26 21:46:46.241] [info]    Electron Logs: C:\Users\Sino\AppData\Roaming\Antigravity\logs\main.log
[2026-05-26 21:46:46.241] [info]  ============================================================
[2026-05-26 21:46:49.715] [error] (node:574304) electron: Failed to load URL: https://127.0.0.1:50935/ with error: ERR_CERT_AUTHORITY_INVALID
(Use `Antigravity --trace-warnings ...` to show where the warning was created)
[2026-05-26 21:46:51.859] [info]  Shutting down language server…




[2026-05-26 21:47:10.742] [info]  [IDE Wizard] Already shown, skipping.
[2026-05-26 21:47:10.745] [info]  Starting app (v2.0.6) with dynamic port…
[2026-05-26 21:47:10.746] [info]  
Spawning: C:\Users\Sino\AppData\Local\Programs\antigravity\resources\bin\language_server.exe --standalone --override_ide_name antigravity --subclient_type hub --override_ide_version 2.0.6 --override_user_agent_name antigravity --https_server_port 0 --csrf_token 6499080b-822f-4ad3-a1b9-80d7ef0189a6 --app_data_dir antigravity --api_server_url https://generativelanguage.googleapis.com --cloud_code_endpoint https://daily-cloudcode-pa.googleapis.com --enable_sidecars
[2026-05-26 21:47:10.851] [info]  [Auto-Restart] Port changed! Reloading all windows with URL: https://127.0.0.1:53610/
[2026-05-26 21:47:10.852] [info]  
============================================================
[2026-05-26 21:47:10.853] [info]    Local:       https://127.0.0.1:53610/
[2026-05-26 21:47:10.853] [info]    LS Logs:     C:\Users\Sino\AppData\Roaming\Antigravity\logs\language_server.log
[2026-05-26 21:47:10.853] [info]    Electron Logs: C:\Users\Sino\AppData\Roaming\Antigravity\logs\main.log
[2026-05-26 21:47:10.854] [info]  ============================================================
[2026-05-26 21:47:18.097] [info]  Shutting down language server…

[Impacted Software]

  • Bitwarden (Desktop App)
  • Antigravity (IDE/Developer tool)
  • Other Electron-based apps utilizing local HTTPS loopback.

Thank you.

2

First, I’m an Avast user and not an Avast Team member. I’m also not using these programs, so I can’t speak from personal experience of this.

Have you tried adding these Apps to the Blocked & Allowed Apps (Avast Menu > Settings > General), see attached screenshot.

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b10227800×461 78.1 KB

3

Thank you for reporting this. Unfortunately the internet is full of “uninstall antigravity advice” and your post was the only one that directed to avast as the culprit. Unfortunately, it is very difficult to contact Avast technical support outseide the US as I am constantly redirected to options like “search our knowledge base”.

I was able to work with Avast and Antigravity alongside just fine until Avast introduced this critical issue without any warning or notification (This app was blocked), let alone a way to remedy the issue.

Adding antigravity to the exceptions under general settings did not help and adding ignore errors flags to the execution of every electron based app seems like a very bad way to handle a trivial bug that Avast should fix and make a way to have both, a functioning computer and a safe one.

Currently until Avast recognizes the severity of the issue (they render a PC to a limited functionality unit) the only reasonable way I was able to find is to disable all core shields when I want to actually work with the computer (including my own electron based local network services).

Anyone who is able to contact Avast and direct them to this bug and unwanted behavior, please do so.

In the meantime, I hope that this post assists others and prevents them from repeatedly uninstall and install antigravity to try and solve this critical bug by avast.

If you are using Avast, I hope you get to this post if you encounter this unwanted behavior (and decide if you prefer to continue avast shields working or the other services):

Antigravity doesn’t load / antigravity black screen / antigravity stuck