Well, well... it's not all as shiny as it did seem to be:

- The .dtsx runs quite fine on the SQL 2008 R2.

- Imported the .dtsx into SQL 2013, corrected...

Hello,

thanks for your help so far.

I have found the problem: in a number of scripts within the .dtsx, the references to libraries were broken.

The developers did forget to mention that...