Better error message for Left hand side of a relation must be a member expression, instead it is

[lprichar]

e.g. "Left hand side of a relation must be a member expression, instead it is Convert(BlahFragment{3f678a79 #2 id=0x7f0a007c 4307669a-ebb7-4998-899f-72f50ebea01d}._beforeTitle.Left)"