idenity provider settings

I’m getting this error:

I’m not able to write to the folder C:\inetpub\wwwroot\news/wp-content/uploads/saml-20-single-sign-on/etc which means you won’t be able to change any settings! Please ensure that the web server has permission to make changes to this folder.

I’ve followed these instructions:
http://www.iis.net/learn/manage/configuring-security/application-pool-identities
But still get the error.

I’m using Microsoft’s WebPI (web platform installer) since this is an internal site to my organization and I have more support with IIS for SSO than Apache.

I’m sure I will have more follow-up questions, but like most troubleshooting I thought I’d start with the issue that seems most obvious.

https://wordpress.org/plugins/saml-20-single-sign-on/