Wrong appearance of a long/integer in a list view

Hi all, I have counted the quantity of objects of an entity. In the debugger I see the right result. In this case 15. In the list view I see 150000,000,000,000,00 Can anybody help me with this problem? Thank you!  
1 answers

Could it be that it is a string that is converted to a long? It feels like it may be something with the used separator.