For the Spanish culture, some of the localization strings are for the German culture.

The following resource keys are the ones containing wrong values:

• PivotInlineFieldList_ValuesEmptyText
  
• PivotInlineFieldList_RowsEmptyText
  
• PivotInlineFieldList_ColumnsEmptyText
  
• PivotInlineFieldList_FiltersEmptyText
  
• Pivot_AggregateSum
  
• PivotFieldList_SetSumAggregate
  
• PivotFieldList_Top10Sum
  
• PivotFieldList_StringFormatDescription

To work around this, you could introduce a custom LocalizationManager and override the GetStringOverride method.

More information about this suggestion can be found here.