Disable modern Lists and libraries at the Site Collection Level
$site = Get-SPSite http://WFE $featureguid = new-object System.Guid "E3540C7D-6BEA-403C-A224-1A12EAFEE4C4" $site.Features.Add($featureguid, $true) #Re-enable modern experience - site collection Level $featureguid = new-object System.Guid "E3540C7D-6BEA-403C-A224-1A12EAFEE4C4" $site.Features.Remove($featureguid, $true)