Can't create challenges

Hi, since today I can't create challenges anymore. Whenever I click "Invite Friends", nothing happens and no link is created. In 'Ongoing Games' there's nothing to be found as well. I don't know how to fix this, logging out and back as well as using a different browser didn't work either.
It may have something to do with me trying to create a challenge in which the locations had to be in a certain order so I created and deleted lots of challenges? I don't know for sure since there was no feedback from the site, something like "You are doing that too often, please try again later"

Is there a way to fix this, do I just have to wait a certain amount of time or how can I access this feature again?

Thanks in advance,
Steve