I have just migrated a project from SSIS 2005 to SSIS 2012
Apart from the project, I had a custom pipeline component, which was also migrated to .NET 4.0, and installed in SQL Server DTS directory and the GAC, as usual.
After the migration, when I tried to open and configure the migrated component I got the error: "Value of null is not valid for stream".
The error only happened in "SSDT for BI" of VS 2012. When I tried to open and use the component in SQL Server Data Tools (VS 2010, not 2012, shell) it work without flaws.
So, this is a problem exclusive to SQL Server 2012 SP1 and SSDT for BI for VS2012
This problem affects SQL Server 2012 SSIS, and, in some occasssions, it doesn't even allow to open SSIS packages.
This error is solved with a Microsoft patch which can be downloaded from this page:
Particularly, to solve the problem in VS, as VS is a 32 bit application, you only have to install the x86 download.