Unable to start pyMAPDL - launch_mapdl - An error occurred when connecting to MAPDL.

[pietverwilligen]

Dear All

I would like to try pyMAPDL (i worked so far only in MAPDL). I am working on a ubuntu 24.04 virtual machine and I have installed a working version of ANSYS 2026R1. My python version is 3.12 and I have installed python3.12-venv and python3.12-full. I installed ansys-mapdl-core in a virtual environment. I am following the instructions on the pyansys website for setup and trouble shooting [1,2]. However I am not able to get the launcher started. The error occurs whith launching mapdl = launch_mapdl.

>>> from ansys.mapdl import core as pymapdl
>>> from ansys.mapdl.core import launch_mapdl
>>> mapdl = launch_mapdl()

I append the output in [3]. Activating the LOG DEBUG, I cannot understand where is the culprit.

>>> from ansys.mapdl.core import LOG
>>> LOG.setLevel("DEBUG")
>>> LOG.log_to_file("mylog.log")
>>> from ansys.mapdl.core import launch_mapdl
>>> mapdl = launch_mapdl(loglevel="DEBUG")

Output is in [4]. I do not attach the mylog.log as the output is the same (and even less ... it does not contain the errors) as given in [4]. Searching in other posts on this forum for people with the same problem, I found that this output of this command might be useful for you: python3 -c "from ansys.mapdl import core as pymapdl; print(pymapdl.Report(gpu=False))", which I have attached at [5]. It tells me that it could not find the grpc package, likely the culprit of all my problems (there are some other packages missing / not found as well).. However when trying to install grpcio, it tells me it is already installed:

pip install grpcio
Requirement already satisfied: grpcio in ./lib/python3.12/site-packages (1.80.0)
Requirement already satisfied: typing-extensions~=4.12 in ./lib/python3.12/site-packages (from grpcio) (4.15.0)

If anyone has an idea what is wrong or has some ideas to debug, I would be happy to try further.
Thanks a lot.
Kind regards
Piet Verwilligen.

[1] https://mapdl.docs.pyansys.com/version/stable/getting_started/launcher.html
[2] https://mapdl.docs.pyansys.com/version/stable/user_guide/troubleshoot.html

[3]

ERROR - pymapdl_global -  launcher - launch_mapdl - An error occurred when connecting to MAPDL.
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/ubuntu/pyMAPDL-venv/lib/python3.12/site-packages/ansys/mapdl/core/launcher.py", line 1880, in launch_mapdl
    raise exception
  File "/home/ubuntu/pyMAPDL-venv/lib/python3.12/site-packages/ansys/mapdl/core/launcher.py", line 1867, in launch_mapdl
    mapdl = MapdlGrpc(
            ^^^^^^^^^^
  File "/home/ubuntu/pyMAPDL-venv/lib/python3.12/site-packages/ansys/mapdl/core/mapdl_grpc.py", line 424, in __init__
    self._configure_transport(ip=ip, port=port, uds_id=uds_id)
  File "/home/ubuntu/pyMAPDL-venv/lib/python3.12/site-packages/ansys/mapdl/core/mapdl_grpc.py", line 556, in _configure_transport
    self.configure_uds(port=port, uds_id=uds_id)
  File "/home/ubuntu/pyMAPDL-venv/lib/python3.12/site-packages/ansys/mapdl/core/mapdl_grpc.py", line 634, in configure_uds
    raise ValueError(
ValueError: UDS socket file /home/ubuntu/.conn/mapdl-50052.sock already exists. Please specify a different port or uds_id.

[4]

DEBUG - pymapdl_global -  launcher - get_start_instance - 'PYMAPDL_START_INSTANCE' is unset, and there is no supplied value. Using default, which is 'True'.
DEBUG - pymapdl_global -  launcher - get_start_instance_arg - Using 'start_instance' equal to True
DEBUG - pymapdl_global -  launcher - get_ip - No IP address was supplied. Using the default IP address: 127.0.0.1
DEBUG - pymapdl_global -  launcher - get_port - Using next available port: 50053
DEBUG - pymapdl_global -  launcher - get_port - Using default port 50053
DEBUG - pymapdl_global -  launcher - get_exec_file - Using default executable.
DEBUG - pymapdl_global -  misc - create_temp_dir - Created run location at /tmp/ansys_khlrapkaio
DEBUG - pymapdl_global -  launcher - get_run_location - Using default temporary directory for MAPDL run location: /tmp/ansys_khlrapkaio
DEBUG - pymapdl_global -  launcher - get_run_location - Using run location at /tmp/ansys_khlrapkaio
DEBUG - pymapdl_global -  launcher - check_lock_file - Checking for lock file
DEBUG - pymapdl_global -  launcher - check_mode - Using mode grpc
DEBUG - pymapdl_global -  launcher - configure_ubuntu - Ubuntu system detected. Adding 'I_MPI_SHM_LMT' env var.
DEBUG - pymapdl_global -  launcher - launch_mapdl - Using additional switches .
DEBUG - pymapdl_global -  launcher - generate_start_parameters - Using start parameters {'additional_switches': '', 'exec_file': '/data/ubuntu/ansys/ansys_2026R1/ansys_inc/v261/ansys/bin/ansys261', 'ip': '127.0.0.1', 'jobname': 'file', 'launch_on_hpc': False, 'nproc': 2, 'override': False, 'port': 50053, 'print_com': False, 'ram': None, 'run_location': '/tmp/ansys_khlrapkaio', 'start_instance': True, 'start_timeout': 45, 'transport_mode': None, 'uds_dir': None, 'uds_id': None, 'certs_dir': None, 'timeout': 45, 'launched': True}
DEBUG - pymapdl_global -  launcher - launch_mapdl - Starting MAPDL
DEBUG - pymapdl_global -  launcher - generate_mapdl_launch_command - Generated command: /data/ubuntu/ansys/ansys_2026R1/ansys_inc/v261/ansys/bin/ansys261 -j file -np 2 -port 50053 -grpc
INFO - pymapdl_global -  launcher - launch_grpc - 
============
============
Running an MAPDL instance
Location:
/tmp/ansys_khlrapkaio
Command:
/data/ubuntu/ansys/ansys_2026R1/ansys_inc/v261/ansys/bin/ansys261 -j file -np 2 -port 50053 -grpc
Env vars:
{'SHELL': '/bin/bash', 'ANSYSPATH': '/data/ubuntu/ansys/ansys_2026R1/ansys_inc/v261/ansys/bin/ansys261', 'PWD': '/home/ubuntu/pyMAPDL-venv', 'LOGNAME': 'ubuntu', 'XDG_SESSION_TYPE': 'tty', 'HOME': '/home/ubuntu', 'LANG': 'C.UTF-8', 'LS_COLORS': 'rs=0:di=01;34:ln=01;36:mh=00:pi=40;33:so=01;35:do=01;35:bd=40;33;01:cd=40;33;01:or=40;31;01:mi=00:su=37;41:sg=30;43:ca=00:tw=30;42:ow=34;42:st=37;44:ex=01;32:*.tar=01;31:*.tgz=01;31:*.arc=01;31:*.arj=01;31:*.taz=01;31:*.lha=01;31:*.lz4=01;31:*.lzh=01;31:*.lzma=01;31:*.tlz=01;31:*.txz=01;31:*.tzo=01;31:*.t7z=01;31:*.zip=01;31:*.z=01;31:*.dz=01;31:*.gz=01;31:*.lrz=01;31:*.lz=01;31:*.lzo=01;31:*.xz=01;31:*.zst=01;31:*.tzst=01;31:*.bz2=01;31:*.bz=01;31:*.tbz=01;31:*.tbz2=01;31:*.tz=01;31:*.deb=01;31:*.rpm=01;31:*.jar=01;31:*.war=01;31:*.ear=01;31:*.sar=01;31:*.rar=01;31:*.alz=01;31:*.ace=01;31:*.zoo=01;31:*.cpio=01;31:*.7z=01;31:*.rz=01;31:*.cab=01;31:*.wim=01;31:*.swm=01;31:*.dwm=01;31:*.esd=01;31:*.avif=01;35:*.jpg=01;35:*.jpeg=01;35:*.mjpg=01;35:*.mjpeg=01;35:*.gif=01;35:*.bmp=01;35:*.pbm=01;35:*.pgm=01;35:*.ppm=01;35:*.tga=01;35:*.xbm=01;35:*.xpm=01;35:*.tif=01;35:*.tiff=01;35:*.png=01;35:*.svg=01;35:*.svgz=01;35:*.mng=01;35:*.pcx=01;35:*.mov=01;35:*.mpg=01;35:*.mpeg=01;35:*.m2v=01;35:*.mkv=01;35:*.webm=01;35:*.webp=01;35:*.ogm=01;35:*.mp4=01;35:*.m4v=01;35:*.mp4v=01;35:*.vob=01;35:*.qt=01;35:*.nuv=01;35:*.wmv=01;35:*.asf=01;35:*.rm=01;35:*.rmvb=01;35:*.flc=01;35:*.avi=01;35:*.fli=01;35:*.flv=01;35:*.gl=01;35:*.dl=01;35:*.xcf=01;35:*.xwd=01;35:*.yuv=01;35:*.cgm=01;35:*.emf=01;35:*.ogv=01;35:*.ogx=01;35:*.aac=00;36:*.au=00;36:*.flac=00;36:*.m4a=00;36:*.mid=00;36:*.midi=00;36:*.mka=00;36:*.mp3=00;36:*.mpc=00;36:*.ogg=00;36:*.ra=00;36:*.wav=00;36:*.oga=00;36:*.opus=00;36:*.spx=00;36:*.xspf=00;36:*~=00;90:*#=00;90:*.bak=00;90:*.crdownload=00;90:*.dpkg-dist=00;90:*.dpkg-new=00;90:*.dpkg-old=00;90:*.dpkg-tmp=00;90:*.old=00;90:*.orig=00;90:*.part=00;90:*.rej=00;90:*.rpmnew=00;90:*.rpmorig=00;90:*.rpmsave=00;90:*.swp=00;90:*.tmp=00;90:*.ucf-dist=00;90:*.ucf-new=00;90:*.ucf-old=00;90:', 'VIRTUAL_ENV': '/home/ubuntu/pyMAPDL-venv', 'SSH_CONNECTION': '192.135.10.240 60508 212.189.205.235 22', 'LESSCLOSE': '/usr/bin/lesspipe %s %s', 'XDG_SESSION_CLASS': 'user', 'TERM': 'xterm-256color', 'LESSOPEN': '| /usr/bin/lesspipe %s', 'USER': 'ubuntu', 'DISPLAY': 'localhost:10.0', 'SHLVL': '1', 'XDG_SESSION_ID': '290', 'VIRTUAL_ENV_PROMPT': '(pyMAPDL-venv) ', 'LC_CTYPE': 'en_US.UTF-8', 'XDG_RUNTIME_DIR': '/run/user/1000', 'PS1': '(pyMAPDL-venv) \\[\\e]0;\\u@\\h: \\w\\a\\]${debian_chroot:+($debian_chroot)}\\[\\033[01;32m\\]\\u@\\h\\[\\033[00m\\]:\\[\\033[01;34m\\]\\w\\[\\033[00m\\]\\$ ', 'SSH_CLIENT': '192.135.10.240 60508 22', 'XDG_DATA_DIRS': '/usr/local/share:/usr/share:/var/lib/snapd/desktop', 'PATH': '/home/ubuntu/pyMAPDL-venv/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin', 'DBUS_SESSION_BUS_ADDRESS': 'unix:path=/run/user/1000/bus', 'SSH_TTY': '/dev/pts/0', 'OLDPWD': '/home/ubuntu', '_': '/home/ubuntu/pyMAPDL-venv/bin/python3', 'I_MPI_SHM_LMT': 'shm', 'ANS_CMD_NODIAG': 'TRUE'}
============
============
DEBUG - pymapdl_global -  launcher - launch_grpc - MAPDL starting in background.
DEBUG - pymapdl_global -  launcher - check_mapdl_launch - Generating queue object for stdout
DEBUG - pymapdl_global -  launcher - check_mapdl_launch - Checking process is alive
DEBUG - pymapdl_global -  launcher - check_mapdl_launch - Checking file error is created
DEBUG - pymapdl_global -  launcher - _check_file_error_created - MAPDL session successfully started (Error file found)
DEBUG - pymapdl_global -  launcher - check_mapdl_launch - Checking if gRPC server is alive.
DEBUG - pymapdl_global -  launcher - _check_server_is_alive - Checking if MAPDL server is alive
DEBUG - pymapdl_global -  launcher - _check_server_is_alive - MAPDL gRPC server successfully launched at: 
DEBUG - GRPC_127.0.0.1:50053 -  mapdl_core - __init__ - Logging set to DEBUG
INFO - GRPC_127.0.0.1:50053 -  mapdl_grpc - _configure_transport - Using UDS transport with socket ID 'mapdl-50053.sock' in directory '/home/ubuntu/.conn'
DEBUG - GRPC_127.0.0.1:50053 -  mapdl_grpc - __init__ - Creating channel to 127.0.0.1:50053
DEBUG - GRPC_127.0.0.1:50053 -  mapdl_grpc - _create_channel - Opening channel at 127.0.0.1:50053
ERROR - pymapdl_global -  launcher - launch_mapdl - An error occurred when connecting to MAPDL.
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/ubuntu/pyMAPDL-venv/lib/python3.12/site-packages/ansys/mapdl/core/launcher.py", line 1880, in launch_mapdl
    raise exception
  File "/home/ubuntu/pyMAPDL-venv/lib/python3.12/site-packages/ansys/mapdl/core/launcher.py", line 1867, in launch_mapdl
    mapdl = MapdlGrpc(
            ^^^^^^^^^^
  File "/home/ubuntu/pyMAPDL-venv/lib/python3.12/site-packages/ansys/mapdl/core/mapdl_grpc.py", line 463, in __init__
    self._channel = self._create_channel(ip, port)  # type: ignore[misc]
                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/ubuntu/pyMAPDL-venv/lib/python3.12/site-packages/ansys/mapdl/core/mapdl_grpc.py", line 746, in _create_channel
    return create_channel(
           ^^^^^^^^^^^^^^^
  File "/home/ubuntu/pyMAPDL-venv/lib/python3.12/site-packages/ansys/tools/common/cyberchannel.py", line 149, in create_channel
    return create_uds_channel(uds_service, uds_dir, uds_id, grpc_options, uds_fullpath)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/ubuntu/pyMAPDL-venv/lib/python3.12/site-packages/ansys/tools/common/cyberchannel.py", line 236, in create_uds_channel
    raise ValueError("When using UDS transport mode, 'uds_service' must be provided.")
ValueError: When using UDS transport mode, 'uds_service' must be provided.

[5]

-------------------------------------------------------------------------------
PyMAPDL Software and Environment Report

Packages Requirements
*********************

Core packages
-------------
ansys.mapdl.core    : 0.72.1
numpy               : 2.4.4
platformdirs        : 4.9.4
scipy               : 1.17.1
grpc                : Package not found
ansys.api.mapdl.v0  : Package not found
ansys.mapdl.reader  : 0.55.2
google.protobuf     : Package not found
ansys-math-core     : 0.2.5
pexpect             : 4.9.0

Optional packages
-----------------
matplotlib          : 3.10.8
pyvista             : 0.47.0
pyiges              : 0.3.2
tqdm                : 4.67.3
ansys-tools-visualization_interface: Package not found
pandas              : Package not found


Ansys Installation
******************
Unable to locate any Ansys installations


Ansys Environment Variables
***************************
ANSYSPATH                      /data/ubuntu/ansys/ansys_2026R1/ansys_inc/v261/ansys/bin/ansys261