Still here trying to solve a bubbling bed with conical inlet. I found someone with a similar geometry also having similar errors just recently (link below), so that’s why I’m posting this as a potential bug. At the moment I get these errors just before (litterally *at* the moment) .vtk’s are written, so I’m starting to think this is related. However, I’m not able to see from the error what actually goes wrong. I have been working on simplifying the case, removing phases etc., so perhaps there are some unremoved remains from previous cases that stir things up. Just a thought. (And, perhaps of interest, as a part of my ongoing troubleshooting, I’ve switched to the Crank-Nicholson scheme, which so far yields a somewhat odd DT plot.)

```
[fedora:468600:0:468629] Caught signal 8 (Floating point exception: floating-point invalid operation)
==== backtrace (tid: 468629) ====
0 /lib64/libucs.so.0(ucs_handle_error+0x2a4) [0x7f4e0e658794]
1 /lib64/libucs.so.0(+0x2a34d) [0x7f4e0e65c34d]
2 /lib64/libucs.so.0(+0x2a62a) [0x7f4e0e65c62a]
3 /home/kjetil/MFiX/3D CSiC/3d_csic_1_2-bedremesh2/mfixsolver.cpython-38-x86_64-linux-gnu.so(__leq_bicgs_mod_MOD_leq_bicgs0+0xc3a) [0x7f4e2da5df5a]
4 /home/kjetil/MFiX/3D CSiC/3d_csic_1_2-bedremesh2/mfixsolver.cpython-38-x86_64-linux-gnu.so(__leq_bicgs_mod_MOD_leq_bicgs+0xf1) [0x7f4e2da5eb81]
5 /home/kjetil/MFiX/3D CSiC/3d_csic_1_2-bedremesh2/mfixsolver.cpython-38-x86_64-linux-gnu.so(__solve_lin_eq_mod_MOD_solve_lin_eq+0x676) [0x7f4e2d9013d6]
6 /home/kjetil/MFiX/3D CSiC/3d_csic_1_2-bedremesh2/mfixsolver.cpython-38-x86_64-linux-gnu.so(__solve_vel_star_mod_MOD_solve_vel_star+0x187c) [0x7f4e2d905aec]
7 /home/kjetil/MFiX/3D CSiC/3d_csic_1_2-bedremesh2/mfixsolver.cpython-38-x86_64-linux-gnu.so(__iterate_MOD_do_iteration+0xe8) [0x7f4e2d6c72d8]
8 /home/kjetil/MFiX/3D CSiC/3d_csic_1_2-bedremesh2/mfixsolver.cpython-38-x86_64-linux-gnu.so(run_mfix_+0x2c5) [0x7f4e2d88c515]
9 /home/kjetil/MFiX/3D CSiC/3d_csic_1_2-bedremesh2/mfixsolver.cpython-38-x86_64-linux-gnu.so(__main_MOD_run_mfix0+0x33) [0x7f4e2d6c9e93]
10 /home/kjetil/MFiX/3D CSiC/3d_csic_1_2-bedremesh2/mfixsolver.cpython-38-x86_64-linux-gnu.so(+0x77bbd) [0x7f4e2d6bdbbd]
11 /home/kjetil/anaconda3/envs/mfix-21.3.2/bin/python3.8(_PyObject_MakeTpCall+0x31e) [0x55929bd2330e]
12 /home/kjetil/anaconda3/envs/mfix-21.3.2/bin/python3.8(_PyEval_EvalFrameDefault+0x53cf) [0x55929bdb96ff]
13 /home/kjetil/anaconda3/envs/mfix-21.3.2/bin/python3.8(_PyFunction_Vectorcall+0x1a6) [0x55929bd97fc6]
14 /home/kjetil/anaconda3/envs/mfix-21.3.2/bin/python3.8(_PyEval_EvalFrameDefault+0xa63) [0x55929bdb4d93]
15 /home/kjetil/anaconda3/envs/mfix-21.3.2/bin/python3.8(_PyFunction_Vectorcall+0x1a6) [0x55929bd97fc6]
16 /home/kjetil/anaconda3/envs/mfix-21.3.2/bin/python3.8(_PyEval_EvalFrameDefault+0xa63) [0x55929bdb4d93]
17 /home/kjetil/anaconda3/envs/mfix-21.3.2/bin/python3.8(_PyFunction_Vectorcall+0x1a6) [0x55929bd97fc6]
18 /home/kjetil/anaconda3/envs/mfix-21.3.2/bin/python3.8(+0x1b0841) [0x55929bd98841]
19 /home/kjetil/anaconda3/envs/mfix-21.3.2/bin/python3.8(PyObject_Call+0x5e) [0x55929bd0d16e]
20 /home/kjetil/anaconda3/envs/mfix-21.3.2/bin/python3.8(+0x253ca9) [0x55929be3bca9]
21 /home/kjetil/anaconda3/envs/mfix-21.3.2/bin/python3.8(+0x1ecea4) [0x55929bdd4ea4]
22 /lib64/libc.so.6(+0x8db17) [0x7f4e86fc1b17]
23 /lib64/libc.so.6(+0x1126c0) [0x7f4e870466c0]
=================================
Program received signal SIGFPE: Floating-point exception - erroneous arithmetic operation.
Backtrace for this error:
#0 0x7f4e86f7675f in ???
#1 0x7f4e2da5df5a in __leq_bicgs_mod_MOD_leq_bicgs0
at /home/kjetil/anaconda3/envs/mfix-21.3.2/share/mfix/src/model/leq_bicgs.f:476
#2 0x7f4e2da5eb80 in __leq_bicgs_mod_MOD_leq_bicgs
at /home/kjetil/anaconda3/envs/mfix-21.3.2/share/mfix/src/model/leq_bicgs.f:91
#3 0x7f4e2d9013d5 in __solve_lin_eq_mod_MOD_solve_lin_eq
at /home/kjetil/anaconda3/envs/mfix-21.3.2/share/mfix/src/model/solve_lin_eq.f:165
#4 0x7f4e2d905aeb in v_m_star
at /home/kjetil/anaconda3/envs/mfix-21.3.2/share/mfix/src/model/solve_vel_star.f:530
#5 0x7f4e2d905aeb in __solve_vel_star_mod_MOD_solve_vel_star
at /home/kjetil/anaconda3/envs/mfix-21.3.2/share/mfix/src/model/solve_vel_star.f:136
#6 0x7f4e2d6c72d7 in __iterate_MOD_do_iteration
at /home/kjetil/MFiX/3D CSiC/3d_csic_1_2-bedremesh2/build/pymfix/iterate.f90:255
#7 0x7f4e2d88c514 in run_fluid
at /home/kjetil/anaconda3/envs/mfix-21.3.2/share/mfix/src/model/mfix.f:188
#8 0x7f4e2d88c514 in run_mfix_
at /home/kjetil/anaconda3/envs/mfix-21.3.2/share/mfix/src/model/mfix.f:142
#9 0x7f4e2d6c9e92 in __main_MOD_run_mfix0
at /home/kjetil/MFiX/3D CSiC/3d_csic_1_2-bedremesh2/build/pymfix/main.f90:81
#10 0x7f4e2d6bdbbc in f2py_rout_mfixsolver_main_run_mfix0
at /home/kjetil/MFiX/3D CSiC/3d_csic_1_2-bedremesh2/build/f2pywrappers/mfixsolvermodule.c:1270
```