Chrome is one of the best and most popular browsers in the world for several reasons: the Google application not only has a reputation for its speed but also for its security. Thanks to automatic synchronization from any device, anyone who creates an account can access the settings made, set favorites and even open tabs from any device. Besides, the look and functionality can be adapted perfectly to your own needs with design templates, applications and extensions, regardless of whether you use a Windows, Linux or MacOS operating system.

But Google’s miraculous weapon, like any other software, is not entirely free of computer problems and errors. The error code “ERR_SSL_PROTOCOL_ERROR “, which informs the user about a failure in the secure connection with the contacted server, is one of the most frequent error messages in this browser. If this site cannot provide a secure connection, what exactly is this SSL connection error, and how can it be corrected?


The times when the web only served as an information platform are a thing of the past. Nowadays, PC browsers and mobile devices are increasingly used to make bank transfers, play online, buy products, store files in the cloud or connect with other users. The fact that more and more personal and sensitive information is being transferred has opened the way to a new type of criminals. Customer data, internal company information and other private data have become the focus of theft in the digital age, which is why SSL and TLS certificates have become necessary.

In today’s article we will show you possible sources of errors and some useful approaches to fixing the “ERR_CONNECTION_CLOSED” error.

This security protocol, which is based on the standard HTTP web protocol, guarantees a secure connection by exchanging certificates. It also ensures that data flows are being transmitted in encrypted form. If you access a website protected by SSL with the Google browser and the secure connection does not work, this site can’t provide a secure connection, this message “net::ERR_SSL_PROTOCOL_ERROR” or when the err_ssl_protocol_error chrome appears. In this way, Chrome informs the user that there is a problem that prevents the exchange of certificates necessary to access the requested web page.

Possible Causes of ERR_SSL_PROTOCOL_ERROR in Chrome

If Chrome displays the error message when trying to access an HTTPS address, the browser also provides the following explanation, very general, about the failure of the connection configuration:

“Unable to establish a secure connection to the server. It is possible that there is a problem with the server or that you need a client authentication certificate. “

You cannot get much information from this description, as it merely indicates that the problem can occur both on the server side and on the client side (the browser). The first is often since the web page contacted has an SSL / TLS certificate, but the licence was not renewed on time and expired. Also, several technical problems may be responsible for the exchange of licenses does not work.

Note : If you suspect that the net::ERR_SSL_PROTOCOL_ERROR on chrome message is due to a server-side error, you can try again to access the web page later. If the problem persists, you should contact the responsible webmaster.

If ERR_SSL_PROTOCOL_ERROR is given on the client’s side, there can also be very different causes. Unlike what appears in the previous description, it is possible that the client has an authentication certificate, and the server cannot find it. Among the most common and known reasons are, for example, the following:

  • the date or time of the system is incorrect
  • a firewall or an antivirus program blocks the web page or the IP address
  • A firewall or antivirus program block SSL / TLS connections
  • the host’s file is corrupted
  • the SSL or the browser cache contains outdated versions of the certificate
  • the Chrome extensions cause the error message
  • The QUIC protocol blocks the establishment of the connection.

Also Read : How to Fix Err_Connection_Closed on Chrome.


The list of possible causes of the err ssl protocol error message makes it clear that there is no general solution. There are several options that you can try to try to solve the problem on chrome err ssl protocol error on your own. First, you can try a “trick” that has proven to be an effective remedy for some web errors: restart your router. Connection problems usually disappear when the device reconnects to the Internet. If the message still appears in Chrome after restarting the device, you can try these solutions to solve ssl protocol error on chrome:

Solution 1: Check the System Date/Time

Since the incorrect configuration of the date and time of the system can prevent the SSL / TLS connection from working, it is recommended that you check the system clock when the message “ERR_SSL_PROTOCOL_ERROR” appears in the Chrome window. If the time does not correspond to the real one or merely an incorrect date is set, the browser often cannot load SSL connections correctly. Make sure the default date and time are correct and adjust them if necessary. You can do it directly from the screen of the taskbar, or you can find the corresponding menu in ” Date and time ” in the control panel.


By default, operating systems automatically configure the correct time values when the device is connected to the Internet, taking into account the time change.

Solution 2: Temporarily Disable Antivirus and Firewall

Software to protect against malware and some firewall is necessary for every user who connects his device to the Internet. However, since these security tools work with different algorithms and rules, they may unintentionally prevent access to individual web pages. For example, it is possible that the IP address or domain address has been classified as a security risk for your computer and, therefore, is blocked. Chrome also offers the message ERR_SSL_PROTOCOL_ERROR when SSL connections are blocked by some tool.
You can quickly check if the security programs you use are the trigger for the error message if you temporarily disable them and try to access the requested web page again. If the connection works now without problems, it means that you have to make changes in the configuration of the programs, for example, remove that IP address from the list of addresses with risk.

Solution 3: Clear the SSL and Browser Cache

In some cases, information stored in the SSL or browser cache can also cause the ERR_SSL_PROTOCOL_ERROR error in Chrome. In this case, you only have to clear the cache to correct the fault.

To do this, open the settings menu in Chrome, which you’ll find at the top right, and select “Settings” from the drop-down menu that is represented by three vertical dots.

err ssl protocol error windows 10

You can also access the configuration menu with the mobile device
Then press the “More tools” button to access the “Clear browsing data” option, with which you will eliminate the Chrome cache.

To clear chrome’s cache and cookies by pressing Ctrl + Shift + Delete. To avoid any infections of devices, keep doing this regularly. 

Advice : You can also go directly to the cache clearing menu by entering the chrome path: // settings / clear Browser Data in the address bar.

err ssl protocol error on chrome

To solve the problem of the certificate, it makes sense to erase all the data from the Chrome cache and not just the ones from the last hours.

The SSL cache, on the other hand, is managed through the operating system itself so it cannot be removed with Chrome. The corresponding function is found in the network and Internet settings, which can be opened in Windows through the control panel.

err ssl protocol error localhost chrome

In the “Networks and Internet” category of the control panel, you can make the most critical settings for local networks and the Internet on Windows devices.

In “Networks and the Internet” you will find the “Internet Options” box, which you must select below. Click on the “Content” tab, and then on “Clear SSL status.”

On most operating systems, such as Windows 7, the SSL cache is called the SSL state.

You will receive a status message when the deletion process has been completed, and you can check if the problem ERR_SSL_PROTOCOL_ERROR has been solved by trying to access the desired page again in Chrome.

ssl cache cleared

The message “The SSL cache has been successfully deleted.” Informs users that Windows has been able to remove the certificate cache.

Also read:

Solution 4: Disable Chrome Extensions

Like any web browser, Google Chrome can be enhanced with add-ons to add additional features, games or new interface designs, for example. However, any further extension carries the risk of damaging browser functionality and causing error messages such as ERR_SSL_PROTOCOL_ERROR. If you have not worked the solutions that we have proposed previously, you can try temporarily disable your Chrome extensions. If the SSL connection is successful, you will know that the cause of the block was an extension. If you activate the extensions one by one, you can identify which of them was the cause of the error.

To get to the extensions control panel, click on the three vertical dots button next to the browser’s search bar, the same menu that we use to clean the Chrome cache. Select ” More tools ” from the drop-down menu and then “ Extensions.”

Note : You can also enter the Chrome: // extensions / path in the browser bar to get directly to the extension manager.

err ssl protocol error

Through the “More tools” menu, you can access not only the Chrome extensions manager but also the developer’s tools or the browser’s task manager.

Disable the enabled extensions one by one, restart Chrome and check if the message ERR_SSL_PROTOCOL_ERROR appears again when entering the corresponding web page.

err ssl protocol error

To reactivate a deactivated extension in Chrome, check the “Activate” box of the corresponding extension.

Solution 5: Disconnect the QUIC Protocol

Google Chrome was one of the first browsers to implement QUIC. As an alternative TCP protocol, it is intended, among other things, to provide additional speed when establishing a connection. Although it is officially in the testing phase, it is already activated by default as an “ experimental protocol ” in several Google services, including Chrome, which may cause an error ERR_SSL_PROTOCOL_ERROR. To solve this problem, sometimes it is enough to deactivate QUIC. To do this, enter the following route in the navigation bar:


The Chrome Flags menu lists all the features that have not yet been officially deployed in the browser. Here you will find the default entry, which in this case means that the QUIC is active. To disable the protocol, select ” Deactivate ” and restart Chrome with the pop-up button.


With Google Chrome, users of the most popular devices (macOS, Windows, Linux, Android) can access the QUIC protocol.

Solution 6: Delete the Hosts’ File or Restore the Default Configuration

Before the domain name system for name resolution on the Internet, an order was established that was based on a local text file that had to be maintained manually. This file called “hosts” still exists today in standard operating systems but is usually used only for the fixed allocation of addresses in local networks.

However, malicious programs can modify the hosts’ file to redirect you to malicious web pages, or they can display error messages like ERR_SSL_PROTOCOL_ERROR. If you delete the file or restore the default configuration (if you have made your settings for the network), you can quickly solve this problem. In Windows, for example, this works in the following way:

  1. Open the “Run” program: simultaneously press the Windows key and the [R] key.
  2. In the window that opens, specify the directory where the hosts’ file is located by inserting the following line (if Windows is not installed in C:, you must enter the appropriate drive letter): C:\Windows\System32\drivers\etc
  3. Confirm the entry by clicking “OK”, and you will access the destination folder where you can select and delete or edit the hosts‘ file.


To edit the hosts’ file, open it with your header text editor.

Users of other operating systems should proceed similarly. The path to access the directory differs from one system to another: users of macOS, Unix, Linux and Android can find the hosts file in / etc /hosts. iOS stores the file in the / private / etc / hosts directory .


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