Bobcares

Fix ERR_SSL_PROTOCOL_ERROR in IIS Express for Visual Studio Projects

by | Jun 18, 2024

Learn how to fix ERR_SSL_PROTOCOL_ERROR in IIS Express for Visual Studio Projects. Our IIS Support team is here to help you with your questions and concerns.

How to Fix ERR_SSL_PROTOCOL_ERROR in IIS Express for Visual Studio Projects

Running into the “ERR_SSL_PROTOCOL_ERROR” while using IIS Express with Visual Studio can be frustrating.

In fact, several of our customers have had trouble with this error. This is why our Experts have put together these effective fixes to get your development environment back on track.

  • Conflicting Localhost SSL Certificates
  • IIS Express using a different SSL port
  • Incorrect SSL certificate permissions
  • Corrupted SSL certificate
  • Incorrect SSL configuration in HTTP.sys

Issue 1: Conflicting Localhost SSL Certificates

If you have previously created your own localhost SSL certificate, it may conflict with the one generated by IIS Express, causing SSL issues.

This can be fixed by deleting all existing localhost SSL certificates from the Personal > Certificates folder in the Local Computer certificate store.

Additionally, we can repair IIS Express via the Visual Studio Installer to force IIS Express to generate a new valid localhost certificate.

Issue 2: IIS Express Using a Different SSL Port

IIS Express reserves the port range 44300-44399 for simulating SSL. So configuring our project to use a different SSL port can lead to issues.

Hence, change the project’s SSL URL to use a port within the 44300-44399 range.

Issue 3: Incorrect SSL Certificate Permissions

How to Fix ERR_SSL_PROTOCOL_ERROR in IIS Express for Visual Studio ProjectsThe private key for the SSL certificate needs the correct permissions set on the MachineKeys folder where it is stored. In other words, incorrect permissions can prevent IIS Express from accessing the private key.

 

So, verify the permissions on the MachineKeys folder. Also, grant needed permissions for the IIS_IUSRS group to access the folder.

Issue 4: Corrupted SSL Certificate

A corrupted SSL certificate can cause SSL handshake failures.

So, backup the existing certificate. Then, replace it with a self-signed certificate and test if the site works over HTTPS. If it does, the original certificate was corrupted and needs to be replaced.

Issue 5: Incorrect SSL Configuration in HTTP.sys

SSL will work only if the HTTP.sys SSL configuration includes the certificate hash and certificate store name for the “IP:Port” pair the client is connecting to. Incorrect configuration will cause SSL negotiation to fail.

We can fix this by using the `netsh http` command to configure the SSL certificate hash and appid for the specific IP:Port pair.

By trying these fixes, we will be able to resolve the “ERR_SSL_PROTOCOL_ERROR” issue and ensure the IIS Express environment runs smoothly with Visual Studio.

[Need assistance with a different issue? Our team is available 24/7.]

Conclusion

In brief, our Support Experts demonstrated how to fix ERR_SSL_PROTOCOL_ERROR in IIS Express for Visual Studio Projects.

0 Comments

Submit a Comment

Your email address will not be published. Required fields are marked *

Never again lose customers to poor
server speed! Let us help you.

Privacy Preference Center

Necessary

Necessary cookies help make a website usable by enabling basic functions like page navigation and access to secure areas of the website. The website cannot function properly without these cookies.

PHPSESSID - Preserves user session state across page requests.

gdpr[consent_types] - Used to store user consents.

gdpr[allowed_cookies] - Used to store user allowed cookies.

PHPSESSID, gdpr[consent_types], gdpr[allowed_cookies]
PHPSESSID
WHMCSpKDlPzh2chML

Statistics

Statistic cookies help website owners to understand how visitors interact with websites by collecting and reporting information anonymously.

_ga - Preserves user session state across page requests.

_gat - Used by Google Analytics to throttle request rate

_gid - Registers a unique ID that is used to generate statistical data on how you use the website.

smartlookCookie - Used to collect user device and location information of the site visitors to improve the websites User Experience.

_ga, _gat, _gid
_ga, _gat, _gid
smartlookCookie
_clck, _clsk, CLID, ANONCHK, MR, MUID, SM

Marketing

Marketing cookies are used to track visitors across websites. The intention is to display ads that are relevant and engaging for the individual user and thereby more valuable for publishers and third party advertisers.

IDE - Used by Google DoubleClick to register and report the website user's actions after viewing or clicking one of the advertiser's ads with the purpose of measuring the efficacy of an ad and to present targeted ads to the user.

test_cookie - Used to check if the user's browser supports cookies.

1P_JAR - Google cookie. These cookies are used to collect website statistics and track conversion rates.

NID - Registers a unique ID that identifies a returning user's device. The ID is used for serving ads that are most relevant to the user.

DV - Google ad personalisation

_reb2bgeo - The visitor's geographical location

_reb2bloaded - Whether or not the script loaded for the visitor

_reb2bref - The referring URL for the visit

_reb2bsessionID - The visitor's RB2B session ID

_reb2buid - The visitor's RB2B user ID

IDE, test_cookie, 1P_JAR, NID, DV, NID
IDE, test_cookie
1P_JAR, NID, DV
NID
hblid
_reb2bgeo, _reb2bloaded, _reb2bref, _reb2bsessionID, _reb2buid

Security

These are essential site cookies, used by the google reCAPTCHA. These cookies use an unique identifier to verify if a visitor is human or a bot.

SID, APISID, HSID, NID, PREF
SID, APISID, HSID, NID, PREF