Privilege exception when creating a datasource

Classic Servoy
1

Sometimes, when I try to create a datasource from a dataset got by query

var vDatasetRateiDip = databaseManager.getDataSetByQuery(globals._serverEpi2, _vQuery, _vArr, 100)    
var vDataSourceRateiDip = vDatasetRateiDip.createDataSource('vDataSourceRateiDip')

I get the following Servoy exception:

Exception Object: com.servoy.j2db.dataprocessing.DataException: user lacks privilege or object not found: VARIAZIONE
MSG: user lacks privilege or object not found: VARIAZIONE
is a ServoyException
Errorcode: 100

user lacks privilege or object not found: VARIAZIONE

com.servoy.j2db.dataprocessing.DataException: user lacks privilege or object not found: VARIAZIONE

I’ve tried many ways to get why this happens (changing column names, defining column types…) but I can’t understand anyway.
It only happens with some columns, apparently random…

Have you ever faced this problem?
Where I’m getting wrong?

2

The problem seems to arise when you have in memory two or more datasource with the same name.
Giving an unique datasource name solves the problem.