Hi,
If i'm not mistaken: since BI4.1 SP05, you can save a .LUMS file to BIPlatform for storage purposes only. (i.e. there is no view or edit mechanism)
However, if you want to Share/View stories via BIPlatform, this requires the Lumira BI-AddOn (which leverages Lumira Server on HANA) and that is currently in Ramp Up. (i.e. not generally available). If you fall into this category, then the support process should be handled via technical support incident.
Regards,
H