iCloud: How to rename a folder on macOS Sierra? I'm trying to rename a folder which I've kept in iCloud.

Mark the folder first and then press return as normal in Finder does not work.

I've tried to google some solution but haven't found anything which has worked.

Are there no way to accomplish that task?

Why is that made that difficult? I really got no idea ...

I'm using a Mac Mini with macOS Sierra.

UPDATE
I have now tried to rename the folder from an iOS device (iPhone). 

There it is similar. 
I get only options for moving and deleting the folder after selecting the folder.

No idea ... Why?
Try renaming your folders from the command line, by typing the following into Terminal:

cd ~/Library/Mobile\ Documents/com~apple~CloudDocs
mv "oldFolderName" "newFolderName"