Using version 10.1 on windows 7 Integrate gives this Simplify::infd Kernel message. What causes it, is this a bug?

ClearAll[a, b, c, x]
Integrate[1/(-Sqrt[b^2 - c^2] + b*Cosh[x] + c*Sinh[x])^(1/2), x]

I checked that the same message shows up in 10.02 and in 9.0

Rubi 4.7 on 10.1, gives an answer which is

  Int[1/(-Sqrt[b^2 - c^2] + b*Cosh[x] + c*Sinh[x])^(1/2), x]
  (*-((Sqrt[2]*ArcTanh[((b^2 - c^2)^(1/4)*Sinh[x + I*ArcTan[b, (-I)*c]])/
             (Sqrt[2]*
         Sqrt[-Sqrt[b^2 - c^2] + 
           Sqrt[b^2 - c^2]*Cosh[x + I*ArcTan[b, (-I)*c]]])])/(b^2 - 
      c^2)^(1/4))
   *)