Setting up OAUTH/REST API on IIS

I'm trying to setup the OAUTH/REST API via IIS 7 on my local machine but I keep receiving this message: 

"The API endpoint is not giving the expected response. Check you followed the instructions correctly. The URL being tested is:"

My web.config is as follows: 

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
    <system.webServer>
        <defaultDocument>
            <files>
                <clear />
                <add value="index.php" />
                <add value="Default.htm" />
                <add value="Default.asp" />
                <add value="index.htm" />
                <add value="index.html" />
                <add value="iisstart.htm" />
                <add value="default.aspx" />
            </files>
        </defaultDocument>
        <rewrite>
          <rules>
		  	<rule name="API Rewrite" stopProcessing="true">
				<match url="^api/*" ignoreCase="false" />
				 <conditions>
					<add input="{REQUEST_FILENAME}" matchType="IsFile" ignoreCase="false" negate="true" />
					<add input="{REQUEST_FILENAME}" matchType="IsDirectory" ignoreCase="false" negate="true" />
				</conditions>
				<action type="Rewrite" url="api/index.php" appendQueryString="true" />
			</rule>
            <rule name="Imported Rule 1" stopProcessing="true">
              <match url="\.(js|css|jpeg|jpg|gif|png|ico|map)(\?|$)" />
              <conditions>
                <add input="{REQUEST_FILENAME}" matchType="IsFile" ignoreCase="false" negate="true" />
              </conditions>
              <action type="Rewrite" url="/404error.php" />
            </rule>
            <rule name="Rewrite Rules" stopProcessing="true">
              <match url="^(.*)$" ignoreCase="false" />
              <conditions>
                <add input="{REQUEST_FILENAME}" matchType="IsFile" ignoreCase="false" negate="true" />
                <add input="{REQUEST_FILENAME}" matchType="IsDirectory" ignoreCase="false" negate="true" />
              </conditions>
              <action type="Rewrite" url="/index.php" appendQueryString="true" />
            </rule>
          </rules>
        </rewrite>
    </system.webServer>
</configuration>

This initially allowed me past the message supplied above, until I setup a local SSL certificate and then the message returned.

Any help would be greatly appreciated.