Last Updated: 15 Apr 2021 07:59 by ADMIN
Created on: 14 Apr 2021 14:22
Type: Bug Report
macOS version doesn't ignore PAC file when unreachable

After installing and launching Fiddler Everywhere 1.6.0 on macOS Big Sur 11.2.3, I am presented with the account login window. No matter if i attempt to create a new account or sign into an existing account, i'm presented with a "Network error" message.

Looking in ~/Library/Application\ Support/Fiddler\ Everywhere/Logs/electron.log, I see:

[2021-04-14 08:53:53:762] [info] Setting the following proxy settings to the main window: {"pacScript":"http://<redacted>","proxyRules":null,"proxyBypassRules":"localhost;;*.local;169.254/16"}

[2021-04-14 08:53:55:831] [error] Error: Error: net::ERR_MANDATORY_PROXY_CONFIGURATION_FAILED
    at SimpleURLLoaderWrapper.<anonymous> (electron/js2c/browser_init.js:105:6497)
    at SimpleURLLoaderWrapper.emit (events.js:315:20)

[2021-04-14 08:53:55:832] [error] Error: net::ERR_MANDATORY_PROXY_CONFIGURATION_FAILED

After looking at the electron log for a bit, and trying to login, the gui now reports: "No internet access and it seems you have a proxy set. Check if it is correct in your OS settings and restart the application after that."

Yes, it is true I have a PAC url. I am also not on the network currently that uses that PAC url. Every other network-using app seems to deal with this ok (browsers, office suite, file sync, etc.).

I request that you handle the PAC url like every other app out there and test for reachability and stand down (i.e. don't use proxy) if not reachable.


1 comment
Nick Iliev
Posted on: 15 Apr 2021 07:59

Hello Adam,


Thank you for reaching out to us and for reporting the issue in detail. I can confirm that the problem is a legit bug on Big Sur with the electron version not working with PAC script. The team is already looking into the possible solutions, and you could expect a patch version as soon as we have a stable one. 

I will regularly update this thread with any new information related to the issue.


Nick Iliev
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