Probs while distributing forms

I have prepared a fillable pdf that I want to distribute via network drive and collect the answers back. Last summer semester it worked wonderfully, now it does not work. The destination folder is accessible for everyone - rwxrwxrwx. But when defining the Acrobat server I get the message "The access path to shared folders is unknown" or "Shared folder could not be created".

I have also noticed that it is not possible to put the server address via drag&drop from e.g. Word, but it is possible to copy it e.g. from notepad. Strange …