Flexible Body Assign Problems

Hi everyone,

I'm modeling a full vehicle event and facing some problems when I try to alter the Rigid body by the Flexible body. With rigid body, my model run well. The error come when I chage body to flexible, the run no longer converge. I recognise It happen because the joint that fix the gear housing of steering boost to the flexible body. When I try to fix it to Chassis (Chassis is Rigid body and was fixed to flexible body) It still run. Could anyone please explain for me why It happen like that and what are comon mistakes leading to disconvergence of model? Below is the log file.

Thanks for your reading and I'm sorry if it is an inscrutable expression.

 Time=1.119E-01; Order=2; H=8.365E-06 [Max Phi=8.134E-11]
 Time=1.121E-01; Order=2; H=1.133E-05 [Max Phi=5.074E-09]
 Time=1.122E-01; Order=3; H=2.474E-06 [Max Phi=1.879E-09]
 Time=1.123E-01; Order=3; H=2.984E-06 [Max Phi=8.737E-11]
 Time=1.123E-01; Order=3; H=5.273E-07 [Max Phi=2.332E-05]
WARNING: [DASPK] The nonlinear system solver in the time integration could not converge
 .....
 Time=1.123E-01; Order=1; H=2.153E-08 [Max Phi=6.221E-05]
 Time=1.123E-01; Order=1; H=2.629E-12 [Max Phi=8.321E-05]
WARNING: [DASPK] The nonlinear system solver in the time integration could not converge
 .....
 Time=1.123E-01; Order=1; H=2.588E-14 [Max Phi=8.669E-05]
WARNING: [DASPK] The nonlinear system solver in the time integration could not converge
 .....
WARNING: [DASPK] The nonlinear system solver in the time integration could not converge
 .....

 DAE SOLVER STATISTICS (DASPK-Index1)
 ------------------------------------------------
 Number of solution steps                 = 556
 Number of residue evaluations            = 1701
 Number of jacobian computations          = 901
 Number of error test failures            = 7
 Number of nonlinear convergence failures = 86

WARNING: Repeated abnormal return from integrator!

ERROR: At time=1.123E-01 the integrator failed to proceed.