Sharepoint - SharePoint 2013 Open Library in Windows Explorer Error
I think the
Desktop experience feature is not installed and
Web client service might be not started so try to follow this
- Open Server Manager –> Manage –> Add Roles and Features.
- Select Features from the left step navigation –> User Interfaces and Infrastructure –> Desktop Experience.
- Click Next then Install.
Restart Server. Go to Services by clicking Run –>
Start WebClient Service. Go back to your document library it's should be working.
Ref: WE’RE HAVING A PROBLEM OPENING THIS LOCATION IN FILE EXPLORER, ADD THIS WEB SITE TO YOUR TRUSTED SITES LIST AND TRY AGAIN
If you are using IE, go to Internet Options > Security > Local intranet > click on "sites" > Advanced > add the website to the zone. You may be have to reload IE to take effect.