Difference in number format (comma and dot) on SSMS and SSIS
The issue here is that the Locale settings of the file connection in SSIS are different to the language settings in SQL Server.

In SSIS, go to the Properties window for your File Connection (Right-click->Properties). There should be a setting for LocaleID that will need to be set to match SQL Server (or to English).

Further information can be found in the following Stack Overflow post