While launching pymapdl_global error occurs in cyberchannel.py creating a UDS channel, part of ansys.tools.common package #4435
Description
🤓 Before submitting the issue
- I have visited the Troubleshooting section.
- I have searched among the existing issues.
- I am using a Python virtual environment.
- I am using the latest version of PyMAPDL and its dependencies (fully updated virtual environment). You can update them using
pip install --upgrade --upgrade-strategy eager ansys-mapdl-corein your activated virtual environment.
🔍 Description of the bug
Simply launching mapdl via pymapdl, UDS transport mode is automatically selected but fails with message:
ERROR - pymapdl_global - launcher - launch_mapdl - An error occurred when connecting to MAPDL.
Traceback (most recent call last):
File "", line 1, in
File "/home/pshutche/pyenv/lib/python3.10/site-packages/ansys/mapdl/core/launcher.py", line 1873, in launch_mapdl
raise exception
File "/home/pshutche/pyenv/lib/python3.10/site-packages/ansys/mapdl/core/launcher.py", line 1860, in launch_mapdl
mapdl = MapdlGrpc(
File "/home/pshutche/pyenv/lib/python3.10/site-packages/ansys/mapdl/core/mapdl_grpc.py", line 463, in init
self._channel = self._create_channel(ip, port) # type: ignore[misc]
File "/home/pshutche/pyenv/lib/python3.10/site-packages/ansys/mapdl/core/mapdl_grpc.py", line 746, in _create_channel
return create_channel(
File "/home/pshutche/pyenv/lib/python3.10/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/pshutche/pyenv/lib/python3.10/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.
🕵️ Steps To Reproduce
import ansys.mapdl.core as pymapdl
mechanical = pymapdl.launch_mapdl()💻 Which Operating System are you using?
Linux
🐍 Which Python version are you using?
3.10
💾 Which MAPDL version are you using?
MAPDL 25R2 SP3
📝 PyMAPDL Report
Show the Report!
-------------------------------------------------------------------------------
PyAnsys Software and Environment Report
-------------------------------------------------------------------------------
Date: Fri Feb 20 11:15:34 2026 CET
OS : Linux (Rocky Linux 8.10)
CPU(s) : 32
Machine : x86_64
Architecture : 64bit
RAM : 187.5 GiB
Environment : Python
File system : xfs
GPU Vendor : Mesa
GPU Renderer : llvmpipe (LLVM 17.0.2, 256 bits)
GPU Version : 4.5 (Core Profile) Mesa 23.1.4
Python 3.10.12 (main, Mar 26 2024, 02:17:48) [GCC 8.2.0]
ansys.mapdl.core : 0.72.0
numpy : 1.26.4
platformdirs : 4.9.2
scipy : 1.15.2
grpc : 1.71.0
ansys.api.mapdl.v0 : Version unknown
ansys.mapdl.reader : 0.55.2
google.protobuf : 4.25.6
ansys-math-core : 0.2.5
matplotlib : 3.10.1
pyvista : 0.46.4
pyiges : 0.3.2
tqdm : 4.67.1
ansys-tools-visualization_interface : Module not found
pandas : 2.2.3
ansys_sphinx_theme : Module not found
ansys.acp.core : Module not found
ansys.dpf.composites : Module not found
ansys.dpf.core : Module not found
ansys.dpf.post : Module not found
ansys.fluent.core : 0.30.2
ansys.fluent.visualization : Module not found
ansys.fluent.parametric : Module not found
ansys.geometry.core : Module not found
ansys.hps.client : Module not found
ansys.math.core : 0.2.5
ansys.mechanical.core : Module not found
ansys.meshing.prime : Module not found
ansys.modelcenter.workflow : Module not found
ansys.motorcad.core : Module not found
ansys.openapi.common : Module not found
ansys.optislang.core : Module not found
ansys.platform.instancemanagement : 1.1.2
ansys.pyensight.core : Module not found
ansys.rocky.core : Module not found
ansys.seascape : Module not found
ansys.simai.core : Module not found
ansys.systemcoupling.core : 0.11.3
ansys.turbogrid.core : Module not found
ansys.tools.report : 0.8.2
ansys.tools.versioning : Module not found
pyaedt : Module not found
pyedb : Module not found
pygranta : Module not found
pytwin : Module not found
appdirs : 1.4.4
pexpect : 4.9.0
-------------------------------------------------------------------------------
Ansys Environment Report
-------------------------------------------------------------------------------
Ansys Installation
******************
No Ansys installations provided
Ansys Environment Variables
***************************
PYMAPDL_MAPDL_EXEC /ott/apps/daily_builds/linx64/v252_Certified_Daily/ansys_inc/v252/ansys/bin/ansys252
ANSYSLI_SERVERS 2325@ottvmlicense1:2325@ottlicense6
FLUENT_MAX_IDLE_TIMEOUT 1440
ANSYSLMD_LICENSE_FILE 1055@ottvmlicense1:1055@ottlicense6
FLUENT_WEBSERVER_TOKEN pshutche
AWP_ROOT251 /home/pshutche/ansys_inc/v251
AWP_ROOT252 /ott/apps/ansys_inc/v2523
📝 Installed packages
Show the installed packages!
ansys-api-fluent==0.3.35
ansys-api-mapdl==0.5.2
ansys-api-platform-instancemanagement==1.1.2
ansys-api-systemcoupling==0.2.0
ansys-api-tools-filetransfer==0.1.1
ansys-fluent-core==0.30.2
ansys-mapdl-core==0.72.0
ansys-mapdl-reader==0.55.2
ansys-math-core==0.2.5
ansys-platform-instancemanagement==1.1.2
ansys-systemcoupling-core==0.11.3
ansys-tools-common==0.4.3
ansys-tools-filetransfer==0.1.1
ansys-units==0.4.0
appdirs==1.4.4
certifi==2025.1.31
charset-normalizer==3.4.1
click==8.1.8
colorama==0.4.6
contourpy==1.3.1
cpylog==1.5.0
cycler==0.12.1
defusedxml==0.7.1
docker==7.1.0
docopt-ng==0.9.0
fonttools==4.56.0
geomdl==5.4.0
googleapis-common-protos==1.69.2
grpcio==1.71.0
grpcio-health-checking==1.62.3
grpcio-status==1.62.3
idna==3.10
importlib_metadata==8.6.1
joblib==1.4.2
kiwisolver==1.4.8
matplotlib==3.10.1
nltk==3.9.1
numpy==1.26.4
packaging==24.2
pandas==2.2.3
pexpect==4.9.0
pillow==11.1.0
platformdirs==4.9.2
pooch==1.9.0
protobuf==4.25.6
psutil==7.0.0
ptyprocess==0.7.0
pyansys-tools-report==0.8.2
pyiges==0.3.2
pyNastran==1.4.1
pyparsing==3.2.1
python-dateutil==2.9.0.post0
pytz==2025.1
pyvista==0.46.4
PyYAML==6.0.2
regex==2024.11.6
requests==2.32.5
scipy==1.15.2
scooby==0.10.0
six==1.17.0
tabulate==0.9.0
tqdm==4.67.1
typing_extensions==4.15.0
tzdata==2025.1
urllib3==2.3.0
vtk==9.5.2
zipp==3.21.0
📝 Logger output file
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# PASTE HERE THE CONTENT OF THE LOGGER OUTPUT FILE.