While using Outlook Exchange profile, you may receive several error messages that indicate that your Outlook certificate has problems. Other applications associated with your Outlook mail account may not work properly either. To solve this problem, you must get to the root of the problem. This is why we have got you this guide to help you learn the potential causes of the Outlook certificate error in detail and the 5 most effective ways to fix it.
When Does Outlook Certificate Error Occur?
When a customer is using either an HTTP connection or a Remote Procedure Call (RPC) for connecting the Outlook profile to the server, they may encounter an Outlook com security certificate error.
What Is the Outlook Certificate Error Messages You May Receive?
- “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. The outlook is unable to connect to the proxy server (Error Code 0)”
- “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 name of the site. The outlook is unable to connect to this server. (%s)”
- “There is a problem with the proxy server’s security certificate, %s. The security certificate is not from a trusted certifying authority. The outlook is unable to connect to this server.(%s)”
- “There is a problem with the proxy server’s security certificate, %s. The outlook is unable to connect to this server. (%s)”
If you are receiving one of the above-mentioned error messages then you surely need to fix the Outlook certificate error auto-discover. But, at first, let us take you through the main causes of it.
Outlook Certificate Error: Main Causes
- Your connection does not have a Certification Authority.
- Outlook access is prevented by third-party extensions or web browsers.
- The name of the site is incorrect on the certificate.
- The Certificate Authority at the root is left unsupported.
- The Outlook certificate is not valid.
One of the aforementioned points can be the reason why you are facing the certificate error on Office 365. However, you can fix the issues on your own just by following the easy fixes mentioned in the next section.
Effective Ways to Fix Outlook Certificate Error
Fixing such critical Outlook errors by a technician can cost you an arm. However, you can easily fix the Outlook certificate error on your own by following these cost-free and effective solutions mentioned below.
Download and Install Trusted Root Certificate
If the Outlook is not able to connect with the proxy server, and you are receiving the Error message 1, install the trusted root certificate. Here are the steps that will come in handy in fixing the Outlook certificate error.
- Open the Certificate dialogue box, navigate towards the ‘Install’ button, and click on it.
- Hit on the ‘Next’ button.
- Under the ‘Store’ checkbox, you will see several options, choose the ‘Place all certificate’ option.
- Then, Click on the ‘Browse’ and proceed.
- Click on the ‘Ok’ after clicking the ‘Trusted Root Certification Authorities’.
- Click on the ‘Next’ tab again.
- Hit the option of ‘Finish’.
- At last, finish the processing of installing Trusted Root Certification Authorities by clicking on the ‘OK’ button.
After applying this troubleshooting method on your system, reboot your device and start the Outlook app without Outlook certificate error auto-discover.
Cross-check the Outlook Certificate and Repair
If the name of the site is incorrect on the certificate or it is invalid, follow the steps to examine and repair the certificate error on Outlook.
- To start examining the certificate, you must open an internet browser.
- Enter the following link in the URL box and click on the enter button:
- Navigate towards the bottom-right corner of the browser and double-click on the ‘Padlock’ gear.
- The further options will be dropped down, click on the ‘Details’ tab.
- You will be asked to provide in the below-mentioned information:
- ‘Valid to’
Here, you must enter the date, month, and year when your Outlook certificate is going to be invalid.
Here, you must enter the name of the site as the subject.
Once you finish entering the aforementioned details, click on the ‘Ok’ button and get rid of the Outlook 2016 certificate error.
Disable Third-party Browser Extensions
You can also encounter any of the error messages mentioned in the article due to third-party add-ins. In this case, you must disable the third-party browser extensions and get rid of the Outlook certificate error.
- Start the Windows system and navigate towards the ‘Applications’ menu.
- To disable the Internet Explorer Browser Extensions, open the Internet Explorer app.
- Locate the ‘Tools menu’ and drop down its options.
- Choose ‘Manage add-ins’.
- Select the ‘Add-ins’ options from the ‘Show’ window and the list of all the active browser extensions will be shown.
- Click on the boxes against the extensions that you want to disable.
- Click on the ‘Disable’.
In case you want to disable all the Internet Explorer extensions, click on the ‘Disable All’.
- Once the Add-ins are disabled, click on the ‘Close’.
- Now restart the Internet Explorer and log in to your Outlook account to confirm that the Outlook certificate error is fixed.
Disable Third-Party Extensions
If the third-party extensions are preventing you from accessing the Outlook app and you are encountering the Outlook certificate error on Office 365.
- To run the Outlook application in Safe mode, go to the ‘Start’ button in the lower-left corner of the screen.
- Find the Run option and open the window and enter the ‘outlook.exe /safe’ text in the blank tab and click on the ‘OK’.
- Once the Outlook application starts in Safe Mode conveniently, you will know that the third-party extensions are only causing the Outlook certificate error on Office 365.
Now, as you know the third-party add-ins are creating problems, follow the rest of the steps, and disable the third-party add-ins.
- Click on the Options from ‘File’ menu options.
- Find and click on the ‘Add-Ins’ option.
- Navigate towards the ‘Manage’ box and choose ‘COM Add-ins’ from expanded options.
- Click on the ‘Go’ button and start looking for the third-party extensions in the list.
- Uncheck the box next to all the third-party add-ins entries and disable it.
- Close the window and restart your Outlook application.
After disabling the Com Add-ins, the Outlook com security certificate error will be resolved successfully.
Check and Change Proxy and DNS Settings
One last and most effective way to fix the Outlook certificate error on Office 365 is to change the proxy settings. Follow the steps mentioned below and learn how to check and change the proxy and DNS settings.
- Move towards the lower-left corner of the screen and click on the ‘Start’.
- In the search bar, type ‘Internet’ and click on the ‘Enter’ button.
- Right-click on the Internet and drop down the Internet options.
- Choose the ‘Connections’ tab and select the ‘LAN Settings’ from ts expanded options.
- On the LAN settings page, navigate towards the ‘Automatically detect settings and verify’.
- Make sure that the box next to its entry is marked, if not, tick the box.
- Click on the ‘Ok’ button if the confirmation message regarding ‘Automatically detect settings’ pops up on your screen.
- Now, click on the ‘Cross’ button to close the app and restart your browser.
Resetting the Proxy and DNS settings will surely help you in getting rid of the Outlook 2016 certificate error.
After following the five quick and effective methods to troubleshoot the Outlook certificate error, you can also do Office.Com/Setup without any error. In case the methods do not resolve your Outlook issue, feel free to talk to our tech experts. Any doubts regarding this content will be solved in the comment section.