SSIS, Excel and 64 Bit SQL Server, wonderful together!
The connection manager "DestinationConnectionExcel" will not acquire a connection because the package OfflineMode property is TRUE. When the OfflineMode is TRUE, connections cannot be acquired.
We've seen similiar errors to this before and I blogged something about, blah blah blah, with a solution like re-installing client tools, before trying that, try this, it's an easier fix and may work. This was found by Tom Reeves, an excellent SQL Server DBA !
Register 32bit dtexec
I ran into this issue yesterday and once in the past and I finally figured out how to fix it quickly. The issue occurs on a 64bit server trying to use the 32bit dtexec command. Typically the package will have an excel connection in it or some another type of object that doesn’t have a 64 bit driver. When you install the 64bit integration services it registers the 64 bit version of DTEXEC, which in turn unregisters the 32 bit version. To fix this you have to register the 32 bit version again. You can do this by running the below code from the server with the issue.
%windir%\syswow64\regsvr32 "%ProgramFiles(x86)%\Microsoft SQL Server\90\dts\binn\dts.dll"