Just changed my internet provider, and got this error again. Connect-PnPOnline : For security reasons DTD is prohibited in this XML document. To enable DTD processing set the DtdProcessing property on XmlReaderSettings to Parse and pass the settings into XmlReader.Create method. Just want to document the solution: 127.0.0.1 msoid.tenantdomain.onmicrosoft.com 127.0.0.1 msoid.onmicrosoft.com   Cheers