From a support forum: In your registry, go to:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft SQL Server\100\ServiceConfigFile
if value is empty then add in:
C:\Program Files\Microsoft SQL Server\100\DTS\Binn\MsDtsSrvr.ini.xml
Installing Service Pack 1 removes data from
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft SQL Server\100\SSIS\ServiceConfigFile
Fresh install of MS SQL server 2008 R2 Standard RTM (with SSIS selected) populates the above registry key with "C:\Program Files\Microsoft SQL Server\100\DTS\Binn\MsDtsSrvr.ini.xml"
Installing Service Pack 1 for MS SQL Server 2008 R2 REMOVES the data, causing SSIS to log Event 274 in the Aplication log.
According to Microsoft, this behavior as “By Design.” Because the default path is not required, the behavior was changed in SP1 to remove it from the registry rather than including it. To remove the warning message, you can re-add the default path to the registry.