Simulation failed error - how to know what went wrong

The following error messages were received after a simulation failed:

produced by Sim4Life version
Rectilinear Discretization to Input File. Elapse Time: 284.204 s
ERROR: Simulation 'broadband' reports the following failure:
ERROR: bad allocation
ERROR: Simulation 'broadband' failed on 2022-Jul-21 10:18:03
ERROR: iSolve framework failed (see previous error messages).
ERROR: The solver process returned an error code:

What does "bad allocation" implies?

do you know what line caused this ?
if not try to comment some code to find reason

"bad allocation" usually refers to errors due to not enough memory. GPUs have limited on-board memory and if the simulation size exceeds this, it fails to run. I would advice to check your system memory status, and if the simulation is too heavy, using a coarse grid (less MCells) can help.