Weird things Happen in motion analysis

what this message all about :( :(

STFINT:MIN_STEP_SIZE HMIN=1.000000000E-7; Reached At Time=1.250000000E-2.
The integrator could not advance the simulation.
An attempt to further decrease the integration step-size failed.
Suggested course of action:
1. Decrease the value of HMIN.
2. Relax the accuracy requirements (ERROR) on the integrator.
3. Increase the number of iterations allowed for convergence.
4. Revisit the way the mechanical system has been modeled.
Last good step-size: 1.791120553E-7.

Please guide