Issue:
When I am trying to open the SharePoint document library I was getting the below error: We’re having a problem opening this location in File Explorer. Add this web site to your Trusted Sites list and try again.
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Also some time I was receiving error as “Your client does not support opening this list with Windows Explorer”
Solution for this issue is:
Follow the appropriate step for your operating system:
– For Windows XP, Windows Vista, and Windows 7,
Start, -> Run -> type services.msc -> Hit Enter.
– For Windows 8
Start -> services.msc-> Hit Enter.
– For Windows Server 2008 or Windows Server 2012
Start -> services.msc -> Hit Enter.
Note: If the WebClient service isn’t present, you must first install the Desktop Experience. For more information about how to install the Desktop Experience, go to the following Microsoft website:
Install Desktop Experience
– Installing desktop experience in Windows Server 2012 r2:
Go to Start -> Administrative Tools -> Server Manager. Then click on Sever Selection.

Select the server and click on Next.

Then in the Select features dialog box, Select Features -> expand “User Interfaces and Infrastructure (2 of 3 installed)” and select “Desktop Experience”.

Then in the Add features that are required for Desktop Experience? Click Add Features like below:

Then choose “Restart the destination server automatically if required”.

Once this feature is installed server will be rebooted. After that start the “WebClient” in services window by following the below steps.
Start -> Services -> click on Services (Services.msc) -> Check for “WebClient” service and start the service.
Now you should be able to open document library in open with explorer view.
I hope this will help you to fix the issue with opening document library in Explorer view. Hope this will be helpful.