Please ensure that both the Public Folders as well as the PST file are linked in Outlook®.
To do so, start Outlook® and display the list of folders. Both the Public Folders as well as the PST file must be listed here.
If the Public Folders are not listed then you are not yet connected with an Exchange®. Please establish this connection first.
If the PST file is not listed, please add this via File, Open, Outlook® Data File.... If the PST file does not yet exist then a new one can be created via the command File, New, Outlook® Data File... and simultaneously linked in Outlook®.
Note for the synchronisation that you are sufficiently authorised to create and delete messages in the Public Folders.
Now please continue with the Public SyncTool configuration.
Note for experienced Outlook® users:
The Public SyncTool can access all established Outlook® profiles. The PST file and the Public folders do not necessarily have to be set up in the same Outlook® profile.