Not able to open a SharePoint modern site using SharePoint Designer

[VigneshGanesan]

Hi Team ,

  We're not able to open a SharePoint modern site using SharePoint Designer .It keeps throwing the an error stating "403 Forbidden" and I'm also attaching the screenshot of that error message in this thread . We have tried with different permission levels but we're still not able to open the site using designer .It's the same case for classic sites as well . 

When we try to check our permissions on the site we get the below mentioned error "

Add, change, or delete HTML pages or Web Part Pages, and edit the Web site using a Microsoft SharePoint Foundation-compatible editor" and the permission level is set to deny 

[#2]

Might I ask what are you trying to do with SPD 2013 when opening a modern SPO site? SPD 2013 can be considered a deprecated tool that clearly has not been modified to support modern SPO sites

[#3]

Have you installed SP1 for SPD 2013?

[#4]

This usually happens because you have to be explicitly added as a site collection admin to the site. Being an owner won’t work. You can do this by using powershell. Set-spouser -loginname user@domain.com -site siteurl -issitecollectionadmin $true

[#5]

Alright .Let me try that

[#6]

@Juan Carlos González Martín same prob here. SO what's the solution MS has provided for workflow? We just moved the new experience all of the stuff Hub and AS , and now me trying to build  WF I am getting same error by SPD. 

[#7]

@VigneshGanesan There is a permission you have to set through PowerShell to allow SharePoint Designer to connect, and to get rid of that error message you see. You have to do it for every site where you want to use SPD.

$cred = Get-Credential

Connect-SPOService -Url https://TENANTNAME-admin.sharepoint.com -credential $cred
Set-SPOSite -Identity https://TENANTNAME.sharepoint.com/sites/SITENAME -DenyAddAndCustomizePages $false

# to test if it changed
$site = Get-SPOSite -Identity https://firemountain.sharepoint.com/sites/Office365Training
$site.DenyAddAndCustomizePages

Disconnect-SPOService

[#8]

in my case I know it's b/s I can't ope modern site in SPD. Well I know MSFT said, You cannot access modern sites using SharePoint Designer. My question is so what's the solution for now until you come up with something? I needed to build this Workflow for now and SharePoint designer is the only tool we're allowed in our org, NO 3rd party tools or Flow/powerapps, these products aren't yet allowed in most Gov sectors including mine. SO what now MSFT? anyone has any idea or information on this? same issue showing me as vignesh ''"403 Forbidden" and same image