Some users may receive a *.dll file when trying to EFILE a return or slips:
[A]Intuit.Tax.Canada.FX2014.InternetFile.SubmissionType cannot be cast to [B]Intuit.Tax.Canada.FX2014.InternetFile.SubmissionType. Type A originates from 'FX2014, Version=1.0.0.0, Culture=neutral, PublicKeyToken=3c7d... in the context 'LoadFrom' at location ?C:Program Files (x86)ProFileFX2014.dll?, Type B originates from ?FX2014, Version=1.0.0.0, Culture=neutral, PublicKeyToken=3c7d...in the context 'Default' at location C:PROGRA~2ProFileFX2014.dll.
When receiving the above error (or similar), this means the ProFile module is not registered with the Windows registry.
Resolution
Run Proreg on the PC and attempt to file the return.
If the above fails, run a repair on ProFile, then attempt to file the return.
If the above also fails, clean uninstall/reinstall ProFile and file the return.