For some time now (perhaps since the 10.13.3 upgrade of MacOS) I have been waking my Mac up from sleep and seeing between 3 and 7 cascading dialogue boxes with the error message:

"Unable to find an application to open URL rstf://?scheduleState=1, with "Ok, Cancel, Find Application" buttons.

I have searched everywhere and cannot find any reference to rstf or scheduleState (there some scheduleState stuff, but it seems unrelated).

Does anyone know how I can find and kill what is trying to open this URL?

Presumably the job is scheduled somewhere, but crontab just has a SuperDuper entry and I've since deleted SuperDuper.

  • 1
    As a test, logout of your account and try another account (create one temporarily if needed) and see if this occurs with the same scenario. Also, does this occur after a restart, or only when awakening from sleep?
    – IconDaemon
    Mar 25, 2018 at 11:15
  • @IconDaemon it occurs after both. Mar 28, 2018 at 5:08
  • Can you post a section of the log where you're seeing that message?
    – Allan
    Mar 29, 2018 at 14:54

2 Answers 2


You can use the RCDefaultApp preference pane to see a list of all URL schemes provided by applications on your system.

These supported URL schemes are defined in the Info.plist of an app, and registered collectively by macOS.

Sadly, I do not have any apps installed that handle rstf:// but please let us know when you find out what it is!


  • 4
    Thanks. I downloaded it and found that rstfp was a URL of the Folx GO downloader app on my system. I'm wondering if that got itself confused along the way. Anyway, I've turned off the scheduler in Folx GO and I'll let you know if it worked. Apr 1, 2018 at 9:42
  • I'd report it as a bug to the creator of that app. Apr 1, 2018 at 18:29
  • Useful app, but it wasn't that app I thought. My next guess is something to do with Evernote. I disabled my account a while back, but still have browser plug-ins floating around. Apr 7, 2018 at 0:48
  • Have you looked in all the various places that things can be scheduled? EtreCheck or CleanMyMac are useful for that. We can solve this. Apr 7, 2018 at 12:55
  • Another idea, you can use Apple's Accessibility Inspector (comes with Xcode) to inspect the window next time it appears and it will clue you in as to what app spawned the window, along with the internal names used on the window. That might shed a little more light on this!? Apr 8, 2018 at 18:37

I faced the same issue. For me, it was Skype that was causing this issue. Here's what I did to resolve it: The solution is:

  1. Open Terminal
  2. Add the following entries to your hosts' file (sudo nano /etc/hosts) rad.msn.com live.rads.msn.com ads1.msn.com static.2mdn.net g.msn.com a.ads2.msads.net b.ads2.msads.net ac3.msn.com apps.skype.com
  3. Ctrl-O, RETURN, Ctrl-X (you are basically adding proxy DNS entries, not allowing the ad URLs to leave your computer with this modification)
  • Thanks for the detailed reply, but no luck for me. I do run skype. I made the changes to hosts file and then shutdown skype. This morning there were three of the dialogue boxes still. Skype isn't running (can't see any skype related processes in Activity Monitor). Mar 28, 2018 at 22:28

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