That is a pity 
I have no further idea.
In your first post you write that applications also give an error, is that still the case?
You just installed, at about the time the last version of Yunohost got released. Are there any updates available for your installation, and does the diagnosis give any warnings?
Maybe something went wrong during the installation?
I don’t know about the noho.st domains, I think someone picks up that thread once in a while.