Access Denied error mapping SharePoint Online library as network drive

SharePoint Online and On-prem both provide an option to map document libraries, folders or even entire sites as a network drive and access the files in familiar Windows explorer view.

But you may face errors while mapping and require IT support for troubleshooting.
One common error is "Access Denied". Yes, even you actually have access to SharePoint.

The mapped network drive could not be created because the following error has occurred:

Access Denied. Before opening files in this location, you must first add the web site to your trusted site list, browse to the web site, and select the option to login automatically.

Perform below checks to get this fixed.

• Add the SharePoint site URL to Trusted Sites list. You may need assistance from IT if you do not have enough rights to do this.
  
  Internet Explorer --> Internet Options --> Security tab --> Trusted sites --> click Sites --> enter "https://*.sharepoint.com" --> click Add
  
  Adding https://*.sharepoint.com will ensure that all SharePoint sites from your Tenant are trusted


• Navigate to Services (services.msc) and confirm the WebClient service is in running state.


• Open Internet Explorer and enter the SharePoint link.
  
  ⭐ Very important, mapping network drive only works with IE at present.


• Enter the login details and select "Keep me signed in" or "Remember me" or "Stay signed in" and click Sign In.
  
  ⭐ This is an important step, you need IE to remember you. If you are unsure if it was selected, sign out and sign in again, then tick the check box. The sign out option is at the top right corner, when you click on your profile picture.

SharePoint remember keep signed in


• Now we are ready to map the network drive, just follow the instructions.
• Navigate to "This PC".
• Click on Computer tab from the top options.
• Click Map network drive.
• Click Map network drive one more time.
• Enter the SharePoint folder path, only till the folder name and click Finish. Keep only till library/folder name and remove everything after it.
  
  Connect using different credentials --> use this option if you are using a personal computer which may not be connected to your organizational network or VPN.
  Reconnect at sign-in --> use this option if you do not want sign in again when the system is rebooted.


• If you have set all necessary configurations correctly, the folder will open directly showing all files which you have access to.
  The mapped drive can be seen under Network Locations.

⚡️ Important Points -

Map network drive uses WebDav to sync SharePoint files, which is an older technology. OneDrive sync client is faster, more secured and even provides Files On-Demand capability.

Currently, the network drive mapping only works with Internet Explorer, not even with Edge. Google Chrome, Safari, Firefox do not support this.

The session expires if you do not login to Internet Explorer regularly. To avoid this, frequently connect to the SharePoint site via IE and make sure you select Stay signed in.