Hi Andres,
I don't know if this maight be the case but I got the same problem aftre upgrading to version 5.0.16. After some searching it seems that this is a bug with this version (for details see
Bug 36098 – "No HTML formatter available for item" when tried to load sharing URL..
My workaround was removing the html extension added to the URL created for the share. The new URL is visible (older versions shares URLs were without html extension)
Hope this helps.
Filippo