One is a <div> element with only a non-existent attribute name of "hidden". E.g.:
JP Kleijn Are you aware of https://developer.mozilla.org/en-US/docs/Web/HTML/Global_attributes/hidden? I think Marius Dumitru Florea used this on purpose and maybe he could clarify this for us. About the second error, I think what we can do to improve is just to silence the variable is case it is not possible/there is nothing to execute a given uix.
