Why is SharePoint Designer unable to open a web site?
(Validate: That the URL is the same, including but not limited to ensuring the HTTP vs HTTPS is correct.) I recommend to check your permission in that web site, ensure you have permission to open that web site in SharePoint Designer.
When do you do not have permission to open a SharePoint site?
You may also get “You do not have permission to open this Web site in SharePoint Designer” error if, at the site collection level, SharePoint designer is not enabled to customize the site using the designer. We can verify from the SharePoint site collection.
Why do I get ” do not have permission ” error in SharePoint Designer?
Based on the SharePoint designer installed in the machine, you can install SharePoint designer SP1 64-bit or SharePoint designer SP1 32-bit. You may also get “You do not have permission to open this Web site in SharePoint Designer” error if, at the site collection level, SharePoint designer is not enabled to customize the site using the designer.
Is it possible to use SharePoint Designer 2013?
If you are using SharePoint 2013 then please make sure that you have the SharePoint Designer 2013 and Office 2013 is a part of the machine i.e. your client machine/desktop/laptop/workstation. This is not just only one issue because of mixed versions, there are so many with respect to Office so best recommendation is as explained above.
How to open a web site in SharePoint?
I recommend to check your permission in the web site, ensure you have enough permission to open the web site in SharePoint Designer. Go to Site Permissions > Permission Level in ribbon > Click the permission you belongs to > Ensure Use Remote Interfaces is selected.
How to remove SharePoint Designer 2013 from Azure?
This can be done under the Conditional Access section of Azure AD. reference Remove SharePoint Designer 2013 related credentials. To do it, open Control Panel > Credential Manager > Windows Credential > Generic Credentials, then delete any items which contains MicrosoftOffice15_Data. Try signing in with your Office 365 account again.