Fix Error 0: There Is a Problem with the Proxy Server's Security Certificate

We all know that Outlook connects with the Exchange Server with HTTPS or RPC connections. While configuring the connection, the SSL certificates act as the catalyst. If there is an issue across the certificates, then Outlook gives multiple errors. Of these errors, Error 0, "There is a problem with proxy server's security certificate," is quite common.

This article is all about discussing the fix of Error 0 across Outlook. If your Outlook is unable to connect to the proxy server, you should give this a read.

Part 1: Major Symptoms of The Error 0 When Outlook Tries Connecting to a Server

Many forms of Outlook Error 0 can occur while connecting to RPC or HTTPS. You may find out the following list of errors while establishing the connection. These mark as the symptoms of Error 0 when Outlook is unable to connect to the proxy server.

Error Message Type 1

There is a problem with the proxy server's security certificate, %s. Outlook is unable to connect with this server. (Error Code 0)

Error Message Type 2

There is a problem with the proxy server's security certificate, %s. The security certificate is not from a trusted certifying authority. Outlook is unable to connect to this server. (Error Code 0)

Error Message Type 3

There is a problem with the proxy server's security certificate. The name on the security certificate is invalid or does not match the name of the target site outlook.office365.com. Outlook is unable to connect to the proxy server (Error Code 0)

Error Message Type 4

There is a problem with the proxy server's security certificate, %s. The name on the security certificate is invalid or does not match the site's name. Outlook is unable to connect to this server. (Error Code 0)

Any of the above problems clearly states the issue across your Outlook account. If you find this error on your computer, you must find a proper solution.

Part 2: Looking into the Causes of the Error 0

While you learn about the symptoms of Outlook Error 0, you need to be aware of what causes it. In this way, you can make appropriate analogies related to the error and its resolution:

Part 3: Major Resolutions That Can Be Applied to the Error 0

With a focused overview of the causes of Outlook Error 0, it can easily assess the resolutions. Therefore, we will target the practical methods that can be easily applied to resolve the error. These resolutions have been marked as specific solutions for different errors discussed above.

Resolution 1: Examine Certificates for Solutions

The first solution involves going through the proxy server security certificate. Where the first two causes have been discussed in the above part, this resolution is for them. If you've been facing such problems specifically, this is the solution to look out for. Let's see how you can examine your certificates to find out a resolution:

Step 1: You must connect to the RPC or any other secure server across Microsoft Internet Explorer.

Type "https://www.server_name.com/rpc" across the address bar if you wish to connect to the RPC server.

Step 2: Find a padlock icon across the lower-right corner of the browser screen and double-click on it.

Following this, lead into the "Details" tab. You need to note down some important information present across the screen.

Step 3: You need to look out for the validation date of the certificate and its subject.

On expiration, you need to get in touch with your administrator. However, if the subject information is different, manually correct it. This would surely resolve the issues caused by Outlook Error 0.

Resolution 2: Trusted Root Certificate Needs to Be Installed

If you are facing the third cause out of the list, you need to go in another direction. For that, you need to install a trusted root certificate. Let's find out how a user can process this with ease:

Step 1: Locate the "Certificate" dialog box and find the option of "Install Certificate."

Click on the option to proceed. You will be required to click on "Next" to proceed with the method.

Step 2: On the next screen, check the option "Place all certificate in the following store."

Proceed to click on "Browse" to lead to the next options.

Step 3: You need to proceed across the "Trusted Root Certification Authorities" option.

Click on "OK" and tap "Next" to finish the process. You will successfully install the trusted root certificate across your device.

Resolution 3: Disable All Third-Party Add-Ins

Do you want to fix the error "There is a problem with proxy server's security certificate?" We have another resolution prepared right here for you. Let's see how you can disable the third-party plugins to solve Outlook Error 0:

Step 1: To start with disabling the third-party add-ins, you need to make some confirmations.

Launch Outlook in Safe Mode by launching the Run program. Type in "outlook.exe /safe" and enter to launch Outlook in safe mode. If it starts, the issue lies across the third-party add-ins installed across Outlook.

Step 2: Launch Outlook on your computer to disable the add-ins and proceed to the "File" tab.

Locate the "Options" button on the left panel and select "Add-ins" from the options. Next, select one of the "Add-ins" and tap on the "Go" button.

Step 3: Clear the check box adjacent to the third-party add-ins that are to be disabled.

Restart your Outlook and have the problems resolved. If you want to disable the third-party browser add-ins, you can perform that across the browser.

Bonus Tip: Fix Your Outlook Data Files with a Proper Email Repairing Tool

What if your Outlook data file is corrupted for any specific reason? Are you confused about the direction you need to take to repair these files? You need to search for the most appropriate solution in this scenario. Wondershare Repairit for Email is designed to function as an email repairing tool. It features a system that is exceptionally easy to work on.

While it provides the ability to repair corrupted OST and PST files, it is pretty consistent. The repairing percentage for Repairit is quite high and absolute. Thus, you should always consider fixing your Outlook data file with this.

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Let's find out how you can repair your Outlook data file with Repairit:

Step 1: Launch Repairit for Email App.

Start Wondershare Repairit for Email on your computer. As you find it as a separate application, it opens up. Click on the "Select File" option to import your Outlook data file.

Step 2: Add your Outlook Data File.

In the next window, you can either find or add a data file across the tool. Click "Find File" and select a drive you have to search. You can also go across the "Add File" section if you know the location.

Step 3: Save your Repaired Outlook Content.

As the files are imported, click "Repair" to start the process. Look across the preview window to find all repaired content. Select the content and click on "Save" to conclude recovery.

Concluding Words

This article has displayed a powerful message about repairing Outlook Error 0. While Outlook features many problems, you can go through the causes to know more about this error. This will help you in deciding the resolutions that suit the case. If you face issues with Outlook data files, you can have them repaired. Wondershare Repairit for Emailoffers a foolproof experience in email repairing.