Warnings and errors related to Cvode

[sachdevakunal]

Hi. I am running the backward step flame by following the tutorial in the documentation. When I add the first level of refinement, after 20 steps, I start getting this warning and error:

 ====================   NEW TIME STEP   ==================== 
 Est. time step - Conv: 1.563627285e-05, divu: 6.049864062e-05
 STEP [281] - Time: 0.001686161945, dt 1.563627285e-05
   SDC iter [1] 
   SDC iter [2] 
[WARNING][rank 0][/home/ksachde4/Downloads/PeleLMeX/Submodules/PelePhysics/Submodules/sundials/src/cvode/cvode.c:1457][CVode] Internal t = 1.43881e-05 and h = 1.81979e-22 are such that t + h = t on the next step. The solver will continue anyway.
[WARNING][rank 0][/home/ksachde4/Downloads/PeleLMeX/Submodules/PelePhysics/Submodules/sundials/src/cvode/cvode.c:1457][CVode] Internal t = 1.43881e-05 and h = 4.54947e-23 are such that t + h = t on the next step. The solver will continue anyway.
[WARNING][rank 0][/home/ksachde4/Downloads/PeleLMeX/Submodules/PelePhysics/Submodules/sundials/src/cvode/cvode.c:1457][CVode] Internal t = 1.43881e-05 and h = 4.54947e-23 are such that t + h = t on the next step. The solver will continue anyway.
[WARNING][rank 0][/home/ksachde4/Downloads/PeleLMeX/Submodules/PelePhysics/Submodules/sundials/src/cvode/cvode.c:1457][CVode] Internal t = 1.43881e-05 and h = 2.84342e-23 are such that t + h = t on the next step. The solver will continue anyway.
[WARNING][rank 0][/home/ksachde4/Downloads/PeleLMeX/Submodules/PelePhysics/Submodules/sundials/src/cvode/cvode.c:1457][CVode] Internal t = 1.43881e-05 and h = 7.10854e-24 are such that t + h = t on the next step. The solver will continue anyway.
[WARNING][rank 0][/home/ksachde4/Downloads/PeleLMeX/Submodules/PelePhysics/Submodules/sundials/src/cvode/cvode.c:1457][CVode] Internal t = 1.43881e-05 and h = 4.44284e-25 are such that t + h = t on the next step. The solver will continue anyway.
[WARNING][rank 0][/home/ksachde4/Downloads/PeleLMeX/Submodules/PelePhysics/Submodules/sundials/src/cvode/cvode.c:1457][CVode] Internal t = 1.43881e-05 and h = 1.11071e-25 are such that t + h = t on the next step. The solver will continue anyway.
[WARNING][rank 0][/home/ksachde4/Downloads/PeleLMeX/Submodules/PelePhysics/Submodules/sundials/src/cvode/cvode.c:1457][CVode] Internal t = 1.43881e-05 and h = 2.77678e-26 are such that t + h = t on the next step. The solver will continue anyway.
[WARNING][rank 0][/home/ksachde4/Downloads/PeleLMeX/Submodules/PelePhysics/Submodules/sundials/src/cvode/cvode.c:1457][CVode] Internal t = 1.43881e-05 and h = 6.94194e-27 are such that t + h = t on the next step. The solver will continue anyway.
[WARNING][rank 0][/home/ksachde4/Downloads/PeleLMeX/Submodules/PelePhysics/Submodules/sundials/src/cvode/cvode.c:1457][CVode] Internal t = 1.43881e-05 and h = 6.94194e-27 are such that t + h = t on the next step. The solver will continue anyway.
[WARNING][rank 0][/home/ksachde4/Downloads/PeleLMeX/Submodules/PelePhysics/Submodules/sundials/src/cvode/cvode.c:1462][CVode] The above warning has been issued mxhnil times and will not be issued again for this problem.
[ERROR][rank 0][/home/ksachde4/Downloads/PeleLMeX/Submodules/PelePhysics/Submodules/sundials/src/cvode/cvode.c:3682][cvHandleFailure] At t = 1.43881e-05 and h = 1.18747e-30, the corrector convergence test failed repeatedly or with |h| = hmin.
 >> PeleLMeX::Advance() --> Time: 1.632812955

 ====================   NEW TIME STEP   ==================== 
 Est. time step - Conv: 6e+199, divu: 5.686372642e-05
 STEP [282] - Time: 0.001701798218, dt 1.719990013e-05
   SDC iter [1] 
[ERROR][rank 0][/home/ksachde4/Downloads/PeleLMeX/Submodules/PelePhysics/Submodules/sundials/src/cvode/cvode.c:3682][cvHandleFailure] At t = 0 and h = 2.25199e-15, the corrector convergence test failed repeatedly or with |h| = hmin.
[ERROR][rank 0][/home/ksachde4/Downloads/PeleLMeX/Submodules/PelePhysics/Submodules/sundials/src/cvode/cvode.c:3682][cvHandleFailure] At t = 0 and h = 2.25199e-15, the corrector convergence test failed repeatedly or with |h| = hmin.
[ERROR][rank 0][/home/ksachde4/Downloads/PeleLMeX/Submodules/PelePhysics/Submodules/sundials/src/cvode/cvode.c:3682][cvHandleFailure] At t = 0 and h = 2.25199e-15, the corrector convergence test failed repeatedly or with |h| = hmin.
[ERROR][rank 0][/home/ksachde4/Downloads/PeleLMeX/Submodules/PelePhysics/Submodules/sundials/src/cvode/cvode.c:3682][cvHandleFailure] At t = 0 and h = 2.25199e-15, the corrector convergence test failed repeatedly or with |h| = hmin.
[ERROR][rank 0][/home/ksachde4/Downloads/PeleLMeX/Submodules/PelePhysics/Submodules/sundials/src/cvode/cvode.c:3682][cvHandleFailure] At t = 0 and h = 2.25199e-15, the corrector convergence test failed repeatedly or with |h| = hmin.

Any idea what might be going wrong?

Thanks.