I have recently started a trial of Mathematica 11.1.1.0 for use in developing a new 3D game engine.
The software works well, aside from the odd issue of not being able to save to Wolfram Cloud. I can create files on the Cloud website itself just fine. After creating a notebook on the cloud, I can then open the file from the cloud locally. What I cannot do is save the file or save a new file to the cloud. I will get a popup window called ‘Wolfram Cloud Activity’ with the filename and next to it, ‘Waiting…’ while both Mathematica and the kernel take up 50% CPU each (adding up to 100% CPU). Both processes will just hang there indefinitely with no network activity.
Oddly enough, I can use the Cloud API methods to save the notebook (as a new, unnamed file). I can also manually upload the file itself to the cloud. The only thing that does not work is saving to the cloud via the GUI (File → Save to Wolfram Cloud…). The process will sit at ‘Waiting…’ taking up CPU until I cancel the “upload” manually.
This is a minor issue at best, but it would be nice to be able to use the in-program feature to save to the cloud without having to manually upload files.
My machine is a Macbook Pro 15" Touchbar Late 2016 model running macOS 10.12.4 if that helps.
If you uninstall your current version, download a new release from user.wolfram.com, and reinstall this new download, does that help? (Otherwise contacting support would again probably be best here for a proper investigation into the issue)
Bruno, are you able to upgrade to the latest release of Mathematica? The issue should be addressed there. If you continue to experience the problems afterwards I would recommend contacting support.