[Hall of Famer]

Well if it cannot locate /install/index.php, chances are the files are not exist or someone has removed them. Did you try reuploading your files?

And I am not quite sure what business 000webhost has against the script, seems to me that they do not have a policy against adoptables sites. It may be some materials you are using/referencing that causes the problem? Consult 000webhost by submitting a ticket, this will help.