Hello Hans I have had an experience similar to yours with manipulates that I deployed and made public. They worked fine for me on my cloud - but others had a hard time getting them to load - even when they are logged onto the cloud. Here is the url to the my last attempt and a screen shot to go along with it. https://notebook.wolframcloud.com/objects/d135e0 8d-165f-4ca9-890e-f9763a07e7d9 and image here.

If I can get these manipulates to work I can use them on my website to replaces the CDF's - which are being phased out by many browsers because of the security risks. (My web site is dynamicsofpolygons.org][1] ) I have no idea what the rules are for outsiders to access these files - a few times it worked if I just removed the 'notebook' part of the url and sent it to Firefox - but now that does not seem to work anymore - so I tried first logging into the cloud - but they just ask for notebooks - which is really stupid - so I click yes and can access the files but they refuse to run. This is very frustrating. Thank you for listening to my rants. Maybe we can help each other. By the way your cloud link behaved exactly the same way mine did - Mathematica accepts it but cannot load it.

Hello Hans I think I am getting to the bottom of this and you will probably not like it. I now have 0 cloud credits and that appears to be the issue. But I cannot even buy cloud credits because I am just a desktop user of Mathematica 10. Instead of getting upset I have taken the next step - which is upgrading to Mathematica 11.1 and it comes with free access to Wolfram On-Line - so Cloud access is much easier. The upgrade was $200, but just to get Mathematica 11 it was worth it and I am already starting to use the Cloud resources. I have signed up to join the Demonstration Project and will be able to publish my manipulates free at the Wolfram site. Eventually I want to take the next step and publish my own manipulates for my web site - but I have to determine what the costs will be. I will let you know how this all progresses. I have been involved with Mathematica for over 20 years and I am still a believer - even though Wolfram reminds me of Donald Trump sometimes. All that matters is the 'bottom line'.