http://support.microsoft.com/kb/2837964/en-us addresses this issue indicating SQL 2012 SP1 with CU4 resolves the issue, it does not. It does appear to remove the random failure, but does not resolve the issue below.
A parent package is run from the SQL Server Agent which calls many child packages via a ForEach loop. The child packages read from a flat file and load to SQL. The incoming files are generated by external clients, many using a manual creation process, files not in the correct format occur. When the flat file connection manager in the child package attempts to up an incorrectly formatted file the Unexpected Termination occurs. For 24 months this same set of packages has run in SQL 2008 R2, when encountering an incorrcetly formatted file an error is emailed and logged, the child package fails, returning control to the parent package which continues to process the remaining file locations.
No errors are logged in SQL 2012 or windows application log when the Unexpected Termination occurs. What can be done to allow the parent package to continue to function?