Calculation error in measure

Impossible de charger les données de cet élément visuel MdxScript(Model) (10, 79) Calculation error in measure 'public invoices'[QtyKg]: Cannot convert value '<pii>2.73</pii>' of type Text to type Number. Réessayez plus tard ou contactez le support. 

It works well in PB desktop, but I have an issue in powerbi services (cant see this graph due to error .

this is a sample of tables used and QtyKg formula:

QtyKg = sumx('public invoices','public invoices'[Qty]*'public invoices'[QtyParam])

and 

QtyParam = RELATED(ParamItems[Qty])

 

So  I use 2 tables. First one is invoices :

Fisrt one is like this 

 and second one is ParamItems:

 Both are linekd with id field (unique value in ParamItems to many in invoices)