Visual Studio 2019: "This site can’t provide a secure connection" on localhost

Question

I've installed Visual Studio 2019 and uninstalled Visual Studio 2017.

Now if I start an ASP.NET (Core) site with https, it always say on Chrome:

This site can’t provide a secure connection

or on Edge

Can’t connect securely to this page

Screenshots:

Chrome:

Edge:

The URLs are correct. This also the same http://localhost:56784/ (it redirects to https)

Tried

What I've tried:

Updated Visual Studio 2019
Create a new ASP.NET Core 2 website
Tested with a ASP.NET site (non core)
Remove IIS certificates with MMC
Checking/changing the IIS settings in Visual Studio 2019 (project properties with context menu and project properties with F4)
Searching on Stackoverflow & Google ;)
Repair Visual Studio 2019

Issue

I think the issue is introduced by:

Installing Visual Studio 2019 and/or,
Uninstalling Visual Studio 2017 and/or,
Updating Windows 10 (current Version: 10.0.18362 Build 18362)

The underlining issue looks like a wrong/old/not supported TLS version?

Question

What can I do to diagnose/fix the problem?

Does this help [Developing locally with ASP.NET Core under HTTPS, SSL, and Self-Signed Certs](https://www.hanselman.com/blog/DevelopingLocallyWithASPNETCoreUnderHTTPSSSLAndSelfSignedCerts.aspx)? Try running `dotnet dev-certs https --trust`. — Dave Anderson, Sep 30 '19 at 22:33
Check the certificate mappings, https://docs.jexusmanager.com/tutorials/https-binding.html and make sure they point to the right certificate. — Lex Li, Oct 01 '19 at 03:17
Thanks for the replies! `dotnet dev-certs https --trust` didn't work unfortunately. Also I don't think this is a certificate issue. I can't see even the certificate in browser as the connection is reset before the certificate is send. — Julian, Oct 01 '19 at 21:52
I've repaired Visual Studio 2019, lost all my extensions installs, and still the same issue is there :'( — Julian, Oct 01 '19 at 21:53

Radu Bartan · Answer 1 · 2020-10-19T13:21:39.147

30

Just as it did not work for @Nosnetrom - repairing IIS 10.0 Express did not work for me either. As @Julian mentioned my problem was caused by uninstalling VS 2017 as well.

This is what did not work for me:

uninstalling / re-installing VS 2019
installing VS 2017
uninstalling / re-installing / repairing IIS 10.0 Express

This is what worked for me:

after reading this advice - I realized that I was using port 51542 instead of a port in the range of 44300 through 44399
then I updated the applicationhost.config file according to this advice. The location of said file on my Windows 10 machine is: C:\Program Files (x86)\IIS Express\config\templates\PersonalWebServer\applicationhost.config. I had to open that file in Notepad ran as an administrator otherwise I could not save these changes:
then in Visual Studio I created a new virtual directory
that seemed to have done the trick for me - when I ran the application it worked

edited Oct 19 '20 at 13:21

answered Oct 05 '20 at 12:21

Radu Bartan

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2

Give this man a medal! This is the only thing that worked for me VS2019 Community on a new machine. – AtLeastTheresToast Dec 15 '20 at 13:29
what if I'm using swagger? will this approach work? I'm having issue since swagger is using http protocol.. – aj go Mar 02 '21 at 04:41
Thank you so much for this solution. This saved me a lot of headache. – Dominic Isaia May 05 '21 at 00:21
This worked for me running an older ASP.NET app in VS2022. In a more modern .NET Core MVC app, I simply had to enable SSL. – Smitty-Werben-Jager-Manjenson Apr 15 '22 at 17:06

score 8 · Accepted Answer · answered Oct 02 '19 at 21:22

8

Repair of IIS Express fixed my problem:

answered Oct 02 '19 at 21:22

Julian

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Thanks for having saved my life! – Canada Wan Aug 27 '20 at 18:11
I have both VS2017 and VS2019, and I have OP's same problem with VS20129. I can't repair IIS Express 10, because my installed version is more recent than the version I downloaded from MS. :-P Any suggestions? – Nosnetrom Sep 17 '20 at 15:24
I'm getting error in repairing IIS..its like looking for a file.. – aj go Mar 02 '21 at 04:43
What does the image said? All of the images are being blocked at my employer's building due to security risk, like virus for example. So what does the image said? Thanks – fletchsod Aug 04 '23 at 18:26

score 7 · Answer 3 · answered Jun 07 '21 at 08:44

7

For those who all the above methods didn't worked:

open a command prompt and then run:

dotnet dev-certs https --clean

and then:

dotnet dev-certs https --trust

answered Jun 07 '21 at 08:44

Vahid Mehrabi

598
10
19

score 6 · Answer 4 · edited May 07 '21 at 10:01

6

None of the above solutions worked for me, Following steps worked for me. Go to chrome or edge browser and type chrome://net-internals/#hsts search for localhost in query domain, you will find lists of domain including localhost. Now delete the domain

Delete the domain by typing localhost

edited May 07 '21 at 10:01

Julian

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answered May 07 '21 at 03:57

Rajon Tanducar

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But then you will use http instead of https after this step? – Julian May 07 '21 at 07:16

score 4 · Answer 5 · answered Jul 01 '21 at 17:16

Just follow below steps:

Close Visual Studio
Delete .vs folder
Restart Visual Studio
Build and Run the Application

As per my understanding, .vs folder keeps the old settings inside the applicationhost.config file. So better to delete all cached settings and start with fresh.

score 2 · Answer 6 · edited Aug 11 '21 at 14:59

2

I solved this problem as follows;

run the web project in debug mode on Visual studio 2019.
if it's on chrome you should do this ;

edited Aug 11 '21 at 14:59

Arvind Maurya

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answered Jan 01 '21 at 13:25

Mustafa Yıldırım

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What do you mean with "reload permanent deletion"? – Julian Jan 01 '21 at 14:10
I mean, Empty Cache and Hard Reload – Mustafa Yıldırım Jan 01 '21 at 14:16

score 2 · Answer 7 · edited Feb 14 '22 at 16:36

None of this worked for me. What did work (and it's not as drastic as the other answers)...

Go into web project and set Start URL and Project URL to this: https://localhost:44365/

Save (but don't run the Project).

Edit .vs/[ProjectName]/config/applicationhost.config and change the bindings for the web project to this:

<binding protocol="https" bindingInformation="*:44365:localhost" />
<binding protocol="http" bindingInformation="*:53269:localhost" />

Reopen Visual Studio and when I started the website it worked.

score 1 · Answer 8 · answered Feb 14 '22 at 07:48

1

In my case use SSL check box was gone in debug section of project properties. everything was fixed by checking again

answered Feb 14 '22 at 07:48

Amir Aghajani

367
2
5

is this the same answer as from Bashar Abu Shamaa / Mar 22 2021 at 14:52? Please update that one! – Julian Feb 14 '22 at 16:34
This worked for me. Not sure how it got unchecked, but thank you! – Smitty-Werben-Jager-Manjenson Apr 13 '22 at 14:46

score 0 · Answer 9 · edited Jun 26 '21 at 13:22

0

Right click on the project, select Properties, 'Debug', check the checkbox "Enable SSL", that's it, worked with me by doing this

edited Jun 26 '21 at 13:22

SendETHToThisAddress

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answered Mar 22 '21 at 14:52

Bashar Abu Shamaa

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score 0 · Answer 10 · edited Feb 14 '22 at 16:35

0

If you 'are using services.AddHttpsRedirection like

services.AddHttpsRedirection(options =>
{
    options.RedirectStatusCode = (int)HttpStatusCode.TemporaryRedirect;
    options.HttpsPort = Configuration.GetValue<int?>("https_port", null);
});

Make sure HttpsPort is null or a valid port in appsettings.json or appsettings.Development.json file.

edited Feb 14 '22 at 16:35

Julian

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answered Feb 11 '22 at 23:38

Sayed Mahmoud

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score -2 · Answer 11 · answered Oct 17 '20 at 05:48

-2

Clear your browser history and cookie

answered Oct 17 '20 at 05:48

dennis

11

This is just guessing. A Secure connection (TLS) is on the presentation layer (or lower), and http (cookie) a least a layer higher, on the application layer. See [OSI model](https://en.m.wikipedia.org/wiki/OSI_model) – Julian Dec 20 '20 at 16:14

Visual Studio 2019: "This site can’t provide a secure connection" on localhost

Screenshots:

Tried

Issue

Question

11 Answers11