Daniel,
You need to ensure that the "EF entity model assembly" and the associated artifact files (*.msl, *.csdl, *.ssdl) can be found at runtime, usually in the working directory.
DevForce EF does add a post-build event to any project referencing the "DEF domain model assembly" to copy these files, but in Beta1 that post-build happens one step too late. If you build a second time it should successfully copy the files.
It's possible that the post-build event was not successfully added to your project, in which case you'll need to either write your own, or manually copy the files to the executable directory. If a post-build was not created for you, please let us know, since that's a bug.
Here's a sample post-build from one of the tutorials:
rem [IdeaBlade-begin]
copy "C:\Head\Learning Units\100 Fundamentals\020 Retrieving Data\02 Tutorials\CS\Completed_Pt1\ServerModelNorthwindIB\bin\Debug\*.csdl" "$(TargetDir)"
if errorlevel 1 goto BuildEventFailed
copy "C:\Head\Learning Units\100 Fundamentals\020 Retrieving Data\02 Tutorials\CS\Completed_Pt1\ServerModelNorthwindIB\bin\Debug\*.msl" "$(TargetDir)"
if errorlevel 1 goto BuildEventFailed
copy "C:\Head\Learning Units\100 Fundamentals\020 Retrieving Data\02 Tutorials\CS\Completed_Pt1\ServerModelNorthwindIB\bin\Debug\*.ssdl" "$(TargetDir)"
if errorlevel 1 goto BuildEventFailed
copy "C:\Head\Learning Units\100 Fundamentals\020 Retrieving Data\02 Tutorials\CS\Completed_Pt1\ServerModelNorthwindIB\bin\Debug\ServerModelNorthwindIB.dll" "$(TargetDir)"
if errorlevel 1 goto BuildEventFailed
copy "C:\Head\Learning Units\100 Fundamentals\020 Retrieving Data\02 Tutorials\CS\Completed_Pt1\ServerModelAw2000\bin\Debug\*.csdl" "$(TargetDir)"
if errorlevel 1 goto BuildEventFailed
copy "C:\Head\Learning Units\100 Fundamentals\020 Retrieving Data\02 Tutorials\CS\Completed_Pt1\ServerModelAw2000\bin\Debug\*.msl" "$(TargetDir)"
if errorlevel 1 goto BuildEventFailed
copy "C:\Head\Learning Units\100 Fundamentals\020 Retrieving Data\02 Tutorials\CS\Completed_Pt1\ServerModelAw2000\bin\Debug\*.ssdl" "$(TargetDir)"
if errorlevel 1 goto BuildEventFailed
copy "C:\Head\Learning Units\100 Fundamentals\020 Retrieving Data\02 Tutorials\CS\Completed_Pt1\ServerModelAw2000\bin\Debug\ServerModelAw2000.dll" "$(TargetDir)"
if errorlevel 1 goto BuildEventFailed
goto BuildEventOK
:BuildEventFailed
echo IdeaBlade post-build event for $(ProjectName) failed
exit 0
:BuildEventOK
echo IdeaBlade post-build event for $(ProjectName) completed Ok
rem [IdeaBlade-end]