The message is issued when the mass matrix associated with the differential algebraic system becomes singular at certain locations during time integration.
Off[message] switches off the message; On[message] switches it on. For example: Off[NDSolve::indexss].
Examples
Basic Examples(1)
The mass matrix associated with certain differential algebraic systems is singular even after index reduction at certain places:
The integration is successful if the singularity can be avoided:
