error in AMS simulation

Hello, I'm stuck with an error in my simulation that prevents me to see any results.

I have a system with one digital block (Verilog) and several analog blocks. I'm using the extracted views (with Calibre Pex) for my analog blocks. I use Cadence Virtuoso 6.1.7 and AMS Unified Netlister with irun. I would like to run a parametric simulation for a few values of the input digital codes of my Verilog block. For each code I run a dc simulation and then a transient.

Unfortunately, I get a red message: sim err  for each simulation. The netlist seems ok. I looked at irun.log and Job Log.

- irun.log shows an error in transient. I copy here what I get.

******************
DC Analysis `dcOp'
******************
Important parameter values:
reltol = 1e-03
abstol(V) = 1 uV
abstol(I) = 1 pA
temp = 27 C
tnom = 27 C
tempeffects = all
gmindc = 1 pS
rabsshort = 1 mOhm
Convergence achieved in 2 iterations.
Total time required for dc analysis `dcOp': CPU = 163.873 s (2m 43.9s),
elapsed = 51.1972 s.
Time accumulated: CPU = 17.907 ks (4h 58m 27s), elapsed = 8.22368 ks (2h 17m
4s).
Peak resident memory used = 24.5 Gbytes.

************************************************
Transient Analysis `tran': time = (0 s -> 25 ns)
************************************************

Notice from spectre during IC analysis, during transient analysis `tran'.
There are 2 IC nodes defined.

Finding DC approximate solution failed. Try again with try_fast_op set to no.
Trying `homotopy = gmin' for initial conditions.

Trying `homotopy = source' for initial conditions.

- Job Log gives me this error message:

INFO (ADEXL-1654): Simulator 'ams' doesn't provide simulation failure
\o information at the analysis level. So 'SkipFailedAnalyses' for option
\o 'evalOutputsOnSimFailure' wouldn't work for this simulator.
\o
\o *Error* Error ID = 5011
\o *Error* Error Msg = Simulator failed to complete the simulation.
\o
\o The simulator process returned a non-zero exit code 137,
\o indicating failure.
\o The simulator could have crashed or
\o intentionally returned to indicate an error.
\o Check the
\o simulator log file for more information. Common causes:
\o 1.
\o Simulator may have crashed during exit even after reporting
\o success in log file.
\o 2. Abrupt automatic simulator
\o termination (e.g., SIGKILL) because the simulator process
\o has
\o exceeded resource limits, which can be specified in
\o the distribution system or
\o by the kernel itself (e.g.,
\o the Linux OOMKiller).
\o 3. Manual termination of the
\o simulator process.
\o ./runSimulation can be manually run in
\o this directory to check the issue.

Both these messages are quite generic and I could not identify the cause of my error. I managed to run the same simulation with schematic views for my analog blocks, but I get these errors when I switch the view to the extracted ones. Could you please suggest me where to look to understand the problem? I need to check my extracted system

Thanks a lot