Using "Services for Object" to attach local files to SAP objects (POs)

As I understand creating an Attachment to a PO for example from local drive - is a standard SAP functionality that does not require configuration, but ... in our Development, Quality and Production systems any document type can be attached, but not in Training. In Training system only .txt documents can be attached and for others it give the error message "Database error with <INSERT INTO KPRO>, error message number SO 013".

1) Does it mean that there is a config for it so certain document types can only be attached? and where can I find it?

2) Is there a way to limit the size of documents that can be attached? since somebody can "accidentally" attach 2 Gig file ...

Thanks,

Paul.