I am getting an error (Cannot handle redirect from HTTP/HTTPS protocols to other dissimilar ones. Invalid URI: The hostname could not be parsed.) in my Umbraco log every minute, as you can see from the following three error log entries:

2016-11-11 16:24:02,177 [10] ERROR Umbraco.Web.Scheduling.ScheduledPublishing - [Thread 12] An error occurred with the scheduled publishing. The base url used in the request was: http://www.mysite.com/umbraco/, see http://our.umbraco.org/documentation/Using-Umbraco/Config-files/umbracoSettings/#ScheduledTasks documentation for details on setting a baseUrl if this is in error
System.Net.WebException: Cannot handle redirect from HTTP/HTTPS protocols to other dissimilar ones. ---> System.UriFormatException: Invalid URI: The hostname could not be parsed.
   at System.Uri.CreateThis(String uri, Boolean dontEscape, UriKind uriKind)
   at System.Uri.CreateUri(Uri baseUri, String relativeUri, Boolean dontEscape)
   at System.Net.HttpWebRequest.CheckResubmit(Exception& e, Boolean& disableUpload)
   --- End of inner exception stack trace ---
   at System.Net.WebClient.UploadDataInternal(Uri address, String method, Byte[] data, WebRequest& request)
   at System.Net.WebClient.UploadString(Uri address, String method, String data)
   at Umbraco.Web.Scheduling.ScheduledPublishing.Run()
2016-11-11 16:25:02,179 [10] ERROR Umbraco.Web.Scheduling.ScheduledPublishing - [Thread 24] An error occurred with the scheduled publishing. The base url used in the request was: http://www.mysite.com/umbraco/, see http://our.umbraco.org/documentation/Using-Umbraco/Config-files/umbracoSettings/#ScheduledTasks documentation for details on setting a baseUrl if this is in error
System.Net.WebException: Cannot handle redirect from HTTP/HTTPS protocols to other dissimilar ones. ---> System.UriFormatException: Invalid URI: The hostname could not be parsed.
   at System.Uri.CreateThis(String uri, Boolean dontEscape, UriKind uriKind)
   at System.Uri.CreateUri(Uri baseUri, String relativeUri, Boolean dontEscape)
   at System.Net.HttpWebRequest.CheckResubmit(Exception& e, Boolean& disableUpload)
   --- End of inner exception stack trace ---
   at System.Net.WebClient.UploadDataInternal(Uri address, String method, Byte[] data, WebRequest& request)
   at System.Net.WebClient.UploadString(Uri address, String method, String data)
   at Umbraco.Web.Scheduling.ScheduledPublishing.Run()
2016-11-11 16:26:02,195 [10] ERROR Umbraco.Web.Scheduling.ScheduledPublishing - [Thread 13] An error occurred with the scheduled publishing. The base url used in the request was: http://www.mysite.com/umbraco/, see http://our.umbraco.org/documentation/Using-Umbraco/Config-files/umbracoSettings/#ScheduledTasks documentation for details on setting a baseUrl if this is in error
System.Net.WebException: Cannot handle redirect from HTTP/HTTPS protocols to other dissimilar ones. ---> System.UriFormatException: Invalid URI: The hostname could not be parsed.
   at System.Uri.CreateThis(String uri, Boolean dontEscape, UriKind uriKind)
   at System.Uri.CreateUri(Uri baseUri, String relativeUri, Boolean dontEscape)
   at System.Net.HttpWebRequest.CheckResubmit(Exception& e, Boolean& disableUpload)
   --- End of inner exception stack trace ---
   at System.Net.WebClient.UploadDataInternal(Uri address, String method, Byte[] data, WebRequest& request)
   at System.Net.WebClient.UploadString(Uri address, String method, String data)
   at Umbraco.Web.Scheduling.ScheduledPublishing.Run()

I don't actually have any scheduled tasks configured in my umbracoSettings.config file (though, I believe Umbraco has some built-in tasks that don't appear in this configuration file). Also, this error doesn't appear to be causing any issues on the website (as far as I can tell), but it's disconcerting nonetheless.

Has anybody come across this error before? Any ideas on what causes it, and what the fix is?

Here is some additional information:

• While this site runs on HTTPS, the error log above mentions an HTTP URL.
• The web.config has <add key="umbracoUseSSL" value="false" />. I suppose that should be set to true. Possibly related?
• Umbraco 7.2.4.