I had a nasty message pop up in the middle of running an SSIS package with DTEXEC. That same package had been working fine for a long time, and was running in BIDS as recently as yesterday on the same machine with no problem.

Error: 2013-04-08 16:04:25.01
   Code: 0xC000F427
   Source: Postcode Zone SSIS.Pipeline
   Description: To run a SSIS package outside of Business Intelligence Development Studio you must install Standard Edition of Integration Services or higher.
End Error

I did a Google search and found other users had often reported this error in other situations where BIDS was not installed; which didn't seem to apply. But one unanswered post caught my eye where someone had added a Derived Column task to the package and had it suddenly fail. That is exactly what I had done!

After some head-bashing I thought maybe there are different versions of DtExec installed locally and I'm using the wrong one:

Get-ChildItem C:\Progra*\dtexec.exe -Recurse | %{
	$version = &$_; 
	$version -like "*Version*"
C:\Program Files\Microsoft SQL Server\110\DTS\Binn\DTExec.exe
Version 11.0.2100.60 for 64-bit

C:\Program Files (x86)\Microsoft SQL Server\100\DTS\Binn\DTExec.exe
Version 10.50.2500.0 for 32-bit

C:\Program Files (x86)\Microsoft SQL Server\110\DTS\Binn\DTExec.exe
Version 11.0.2100.60 for 32-bit

I'd been using the first (2008R2) version for some reason. Switching to the last (2012 32-bit) version made it work.