"Your connection is not private" whenever I start Fiddler

[Avrohom Yisroel]

Hello,

As soon as I start Fiddler, any attempt to connect to a secure web page fails with the message "Your connection is not private" in my web browser.

What's going on?

 Thanks

[Eric Lawrence]

Hi, 

This generally indicates that you have enabled HTTPS decryption but haven't configured Windows (or Firefox, if you're using Firefox) to trust Fiddler's root certificate.

The simplest thing to do would be to follow these steps, and when asked if you'd like Windows to trust Fiddler's root certificate, choose "Yes."

http://textslashplain.com/2015/10/30/reset-fiddlers-https-certificates/


Regards,
Eric Lawrence
Telerik

[Avrohom Yisroel]

I'm actually using Chrome, but I checked it in IE as well, and got the same issue. Anyway, I'll give that a go and see what happens.

Thanks

[Avrohom Yisroel]

Turns out the answer was simple. I was using version 2.6.2, whereas I should have been using 4.6.2. I uninstalled, installed the latest and it works fine.

Thanks

[Gene]

Just installed 4.6.2.0.  Selected to decrypt HTTPS, exported the Fiddler self-signed root, imported it under Windows 7 Trusted Root CA using certmgr.msc, and verified Windows trusts it.  Then imported it into Firefox 44.0.2 Advanced > Certificates > View Certificates > Authorities with Trust Setting to Identify Websites.  Every https reference when Fiddler is running, regardless of browser, gives "Your connection is not secure" error.  If I close Fiddler, no errors.  Rebooted, no change.  Not sure what I'm doing wrong.

TIA, Gene

[Tsviatko Yovtchev]

Hello,

Could you, please, try following these steps:

1. Click Tools > Fiddler Options.
2. Click the HTTPS tab.
3. Ensure that the text says Certificates generated by CertEnroll engine.
4. Click Actions > Reset Certificates. This may take a minute.
5. Accept all prompts

Regards,

Tsviatko Yovtchev
Telerik

[Gene]

Thank you Tsviatko.  After executing the steps you provided (and importing the new cert into Firefox), all https requests work properly from all browsers, and Fiddler is properly capturing.

Can you tell me what the problem was, and what may have caused it?

[Tsviatko Yovtchev]

Hi,

Well Fiddler has upgraded certificates infrastructure. This - http://textslashplain.com/2015/10/30/reset-fiddlers-https-certificates/ (also mentioned previously) explains it.

Regards,
Tsviatko Yovtchev
Telerik

[Neyla]

I have Fiddler installed on my machine. I have installed the Fiddler Root Certificate to decrypt HTTPS traffic, but it only works in FF and IE, not in chrome. Chrome does not trust Fiddler's certificate and does not allow me to connect to any tunneled connections.
I tried looking on Fiddler2.com's page for a plugin but I don't see anyhing.

[Neyla]

I have Fiddler installed on my machine. I have installed the Fiddler Root Certificate to decrypt HTTPS traffic, but it only works in FF and IE, not in chrome. Chrome does not trust Fiddler's certificate and does not allow me to connect to any tunneled connections.
I tried looking on Fiddler2.com's page for a plugin but I don't see anyhing https://bluestacks.vip/  https://textnow.vip/    https://photomath.vip/

[Alexander]

Hi,

Which version of Chrome are you using? Also, would it be possible to navigate to a page, where Chrome says "Your connection is not private", hit F12 and go to the Security tab? There shoould be some information why the certificate is not trusted.

Regards,
Alexander
Progress Telerik

[Bashar]

I did all steps But!

This page is not secure (broken HTTPS).
Certificate - insecure (SHA-1)
The certificate chain for this site contains a certificate signed using SHA-1.
View certificate

Certificate - Subject Alternative Name missing
The certificate for this site does not contain a Subject Alternative Name extension containing a domain name or IP address.
View certificate

Certificate - missing
This site is missing a valid, trusted certificate (net::ERR_CERT_COMMON_NAME_INVALID).
View certificate
===================================

Chrome : 68.0.3440.106 (Official Build) (32-bit)

Fiddler Https Interface : https://i.imgur.com/c5GKSNl.png

 

[Barry]

i think something is wrong with the SSL certificate  

[Bradley]

Im having the same error.

Are you using centralised certs by any chance?

[Carlton]

I have followed the documentation and exported the fiddler cert to my machine, did the trust certificate through windows cert management and then in Settings for Chrome and Firefox I added the cert but still I get security denial when hitting any https site with Decrypt HTTPS traffic checked. jiofi.local.html forpc

[Keith]

Gotcha I ran into:  resetting Windows Root Certs did not work, turns out I still had the old CertMaker DLL installed.  Uninstalled the old CertMaker plugin, noticed Fiddler certs are now generated by CertEnroll, reset Root Certs, and voila.

Thorny problem that caused a wonky error:  Outlook would disconnect from Exchange whenever Fiddler was not running (even if traffic capture was turned off).

[tech]

Thanks for sharing this information. for pc

[Jitendra]

Here is how to fix Your Connection is Not Private Error In Chrome
One of the main reasons behind such an error may be the wrong date and time settings. The SSL might fail to fetch data from the server when an inaccurate date is provided. To change them, go to Date and Time under Settings in your system, and choose the option Set Time Automatically. This helps in securing loading of data.
Slide the bar below Set Time Automatically to turn it on.This lets the system to fetch time directly from the network, thus providing accurate measures.
Source:- http://merabheja.com/connection-not-private-error-in-chrome/

[soanl]

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[Lairger]

Fiddler normally is a valid network analysis tool, but I hope some malware/virus did not auto-install it with an invalid root cert for bad purposes.  Have you run an antivirus scan on your computer?

To remove any untrusted certificates from your Windows computer, try the following:

1. Click Start, type certmgr.msc in the search box and press Enter.
2. In the left panel, navigate to Untrusted Certificates and then expand Certificates.
3. Right click on the certificates you wish to remove and choose Delete.

[Hare]

This feature works by periodically checking whether Fiddler is running, and automatically adjusting the proxy settings based on that check. If you click on the status bar panel, a popup menu enables you to change your FiddlerHook settings.

[Nick Iliev]

Hi Carlton,

 

The "Your connection is not private" screen might appear due to multiple reasons that could not be strictly related to Fiddler. I've tried the provided HTTPS endpoint, and it is captured directly with no hassle on my side.

HTTP/1.1 200 OK
Date: Tue, 03 Nov 2020 09:56:40 GMT
Server: Apache
X-UA-Compatible: IE=edge
Link: <https://jiofilocalhtml.run/wp-json/>; rel="https://api.w.org/", <https://jiofilocalhtml.run/wp-json/wp/v2/pages/6>; rel="alternate"; type="application/json", <https://jiofilocalhtml.run/>; rel=shortlink
Upgrade: h2,h2c
Connection: Upgrade, Keep-Alive
Vary: Accept-Encoding
Content-Length: 41149
Keep-Alive: timeout=5, max=75
Content-Type: text/html; charset=UTF-8

I would suggest checking the points listed here (especially the ones about the computer clock, the expired TSL, clearing the browser cache, trying incognito).

 

If you still have the issue, you could also try the new Fiddler Everywhere and see if the automatic certification installation works on your side (for example, through Fiddler Everywhere and Chrome).

 

Regards,
Nick Iliev
Progress Telerik

[alex]

It happens when to try to browse the website which has no security plugin or certificate, to prevent this error you need to install SSL certificate on your website. Furthermore you can check this guide it will help you: https://www.cloudways.com/blog/wordpress-ssl/

[alex]

It happens when you are visiting a website which is not secure of don't have SSL installed, Checkout this guide to learn more about Fixing this error: https://www.cloudways.com/blog/wordpress-ssl/

[Monika]

This feature works by periodically checking whether Fiddler is running, and automatically adjusting the proxy settings based on that check. If you click on the status bar panel, a popup menu enables you to change your FiddlerHook settings. Login to JioFi Admin Panel using jiofi.local.html with the default Username and Password given on the Box.

[Izwa]

I am using so many users' data in my website and database. Will it cause any issue when I use Fiddler on my web platform? The answer will be much appreciated. I need a direct answer. Please answer me.

[Nick Iliev]

Could you elaborate more on how you plan to use Fiddler on your web platform? If you are thinking of using it as a 24/7 service to monitor the traffic - then it is probably not a good idea as it is a UI tool meant for debugging and not for non-stop monitoring (FiddlerCore is the library you could use to create your own app to achieve that)

[Carlton]

1. Open Chrome.

2. Press CTRL + SHIFT + N keys together from your keyboard to open chrome in incognito mode and try opening the website again.

[tech]

I think something is wrong with the SSL certificate.