Using "Model Entities" Module to Create Custom Entities
I know this question is a little old, but just in case you (or others) still need assistance...
Make sure the hook_views_default_views() was renamed properly.
If your module name is "client" then it should be client_views_default_views().

I was recently working with the Model Entities module and ran into the same issue. Turns out I missed renaming that function.

If it's named correctly, then I suggest comparing your file to the model.views.inc file to find the difference.