ERR_CON­NEC­TION_CLOSED: How to fix the con­nec­tion error

Before you delve deeply into the con­fig­ur­a­tion of the system and browser to find the source of the "ERR_CON­NEC­TION_CLOSED" error and fix it, first check your internet con­nec­tion. With Windows, for example, you can do this via the network symbol in the no­ti­fic­a­tion area (also called the System Tray). There you can see not only the network to which you are currently connected, but also the con­nec­tion status.

Con­nec­tion problems that lead to errors such as the "ERR_CON­NEC­TION_CLOSED" message may also be due to errors in the system's TCP/IP setup. However, you can solve this problem by resetting the settings for the TCP/IP stack to their original state. All you need is ad­min­is­trat­or rights and the command line tool Netshell (netsh), which has been installed by default since Windows 2000. To start the command prompt as an ad­min­is­trat­or, first access the Start menu (Windows icon) and enter the term "cmd" in the search bar. Then right-click on the cmd ap­plic­a­tion presented as a search result and select "Run as ad­min­is­trat­or":

Proxies and VPN con­nec­tions offer you - each in their own way - the pos­sib­il­ity of remaining anonymous during your time on the internet. Both solutions are actively involved in the data transfer process, which is why they can also cause com­plic­a­tions and, for example, cause the "ERR_CON­NEC­TION_RESET" error. If you use one of the two bridging tech­niques, you should de­ac­tiv­ate it - at least for testing purposes - or - in the case of VPN - not use it. To de­ac­tiv­ate the proxy server, you need the "Internet settings" menu, which can be accessed via the control panel:

Then switch to the "Con­nec­tions" tab. In the upper window you will find a list of con­figured VPN and dial-up con­nec­tions. If you have set up a VPN con­nec­tion, you can also simply delete it here using the "Remove" button:

The con­fig­ur­a­tion of the proxy settings works via the "LAN settings" option, which can be found in the lower part of the window:

This will open the DNS settings in the hidden options menu "Net Internals". In addition to a list of valid and expired DNS entries, here you will find the "Clear host cache" button, which can be used to clear the cache.

It’s not only the cache of the used DNS server that can become a problem: If the avail­ab­il­ity of the server is limited or the server is com­pletely down, the con­nec­tion may also be in­ter­rup­ted and the Chrome error message may appear. Usually you obtain the address of the DNS server auto­mat­ic­ally, so that you are assigned a local nameserv­er from your internet provider. However, you have the option of entering the server manually and thus trans­fer­ring the name res­ol­u­tion task to another server in order to fix the "ERR_CON­NEC­TION_CLOSED" message. To do this, proceed as follows:

Open the overview of active network con­nec­tions, for example via the Network and Sharing Center or the key com­bin­a­tion [Windows key] +[R] followed by the entry "ncpa.cpl".

Right-click on the network con­nec­tion via which you are connected to the internet and click on "Prop­er­ties" in the pop-up menu (requires ad­min­is­trat­or rights). Search for the entry "Internet Protocol Version 4 (TCP/IPv4)" and open the protocol’s con­fig­ur­a­tion menu by double clicking. Leave the IP address settings unchanged (auto­mat­ic­ally or manually entered address) and select the option "Use the following DNS server addresses" in the lower area of the menu. Then enter the server addresses of your choice. For example, the addresses of Google servers (8.8.8.8.8 and 8.8.4.4) are re­com­men­ded:

Even the best security setup does not offer 100% pro­tec­tion against malware. Therefore, you can never rule out that your system has been infected with malicious software and this is what’s causing the dis­con­nec­tions. For this purpose, Chrome offers its own solution for detecting and removing malware, which you can start directly in the browser settings. To do this, open the settings menu by clicking on the three-point symbol and selecting "Settings":

Select "Advanced" to expand the advanced options menu. Under "Reset and clean up" you will find the "Clean up computer" button, which leads you to the cleanup tool:

To start the tool, click on "SEARCH". If you don't want Chrome to collect in­form­a­tion about detected malware as well as your system settings and processes, you need to move the slider to the left under "Report details to Google".

Ex­ten­sions in Chrome are important building blocks for extending the func­tion­al­ity of the Google browser. There are thousands of free ex­ten­sions available in the Chrome Store, which are extremely practical in principle, but also cause problems such as the "ERR_CON­NEC­TION_CLOSED" error - es­pe­cially if the ex­ten­sions are no longer com­pat­ible with the current browser version. To check whether an installed extension is the cause of the error message, de­ac­tiv­ate it tem­por­ar­ily. Simply enter the URL chrome://ex­ten­sions in the address bar and move the sliders below each extension to the left:

Chrome then checks if the current version is installed and auto­mat­ic­ally starts the update process if you are using an outdated version. If your browser is up to date, you will see the message "Google Chrome is up to date":