Bug located in ... launch fluent command

[abhi-bmi]

🔍 Before submitting the issue

• I have searched among the existing issues
• I am using a Python virtual environment

🐞 Description of the bug

So In my local machine i am able to launch fluent successfully. but in corvid I am getting an error when i am launching it with gui.
/opt/Software/corvid/ansys/v251/fluent/bin/fluent 3ddp -py -t4 -sifile=/tmp/serverinfo-agr1p3p8.txt -nm

so by default it's taking -nm (no monitor) even though i say ui_mode='gui' . How to remove that -nm argument by using python's pyfluent below is the command i am using to launch the fluent
solver = pyfluent.launch_fluent(precision='double', processor_count=4, mode='solver', ui_mode='gui', py=True, product_version=r'25.1',) # Tried with py=True and py=False getting same error.

📝 Steps to reproduce

Launch the fluent with the above command, in server it fails with below error :
/opt/Software/corvid/ansys/v251/fluent/fluent25.1.0/cortex/lnamd64/cortex.25.1.0 -f fluent -py -sifile=/tmp/serverinfo-kbzdnmqi.txt -nm (fluent "3ddp -pdefault -host -r25.1.0 -t4 -mpi=intel -path/opt/Software/corvid/ansys/v251/fluent -ssh")
pyfluent.launcher ERROR: Exception caught - RuntimeError: An error occurred in the server while evaluating the Scheme expression
Traceback (most recent call last):
File "/home/afj/shared/pyFluent/venv/lib/python3.11/site-packages/ansys/fluent/core/launcher/standalone_launcher.py", line 281, in call
session = self.new_session._create_from_server_info_file(
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/afj/shared/pyFluent/venv/lib/python3.11/site-packages/ansys/fluent/core/session.py", line 332, in _create_from_server_info_file
fluent_connection = FluentConnection(
^^^^^^^^^^^^^^^^^
File "/home/afj/shared/pyFluent/venv/lib/python3.11/site-packages/ansys/fluent/core/fluent_connection.py", line 465, in init
self._connection_interface.get_cortex_connection_properties()
File "/home/afj/shared/pyFluent/venv/lib/python3.11/site-packages/ansys/fluent/core/fluent_connection.py", line 309, in get_cortex_connection_properties
logger.info(self.product_build_info)
^^^^^^^^^^^^^^^^^^^^^^^
File "/home/afj/shared/pyFluent/venv/lib/python3.11/site-packages/ansys/fluent/core/fluent_connection.py", line 301, in product_build_info
build_info = self._app_utilities.get_build_info()
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/afj/shared/pyFluent/venv/lib/python3.11/site-packages/ansys/fluent/core/services/app_utilities.py", line 192, in get_build_info
build_time = self.scheme.eval("(inquire-build-time)")
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/afj/shared/pyFluent/venv/lib/python3.11/site-packages/ansys/fluent/core/services/scheme_eval.py", line 374, in eval
return self._eval(val, suppress_prompts)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/afj/shared/pyFluent/venv/lib/python3.11/site-packages/ansys/fluent/core/services/scheme_eval.py", line 296, in _eval
response = self.service.scheme_eval(request, metadata)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/afj/shared/pyFluent/venv/lib/python3.11/site-packages/ansys/fluent/core/services/scheme_eval.py", line 97, in scheme_eval
return self.__stub.SchemeEval(request, metadata=new_metadata)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/afj/shared/pyFluent/venv/lib/python3.11/site-packages/grpc/_interceptor.py", line 277, in call
response, ignored_call = self._with_call(
^^^^^^^^^^^^^^^^
File "/home/afj/shared/pyFluent/venv/lib/python3.11/site-packages/grpc/_interceptor.py", line 329, in _with_call
call = self._interceptor.intercept_unary_unary(
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/afj/shared/pyFluent/venv/lib/python3.11/site-packages/ansys/fluent/core/services/interceptors.py", line 172, in intercept_unary_unary
return self._intercept_call(continuation, client_call_details, request)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/afj/shared/pyFluent/venv/lib/python3.11/site-packages/ansys/fluent/core/services/interceptors.py", line 162, in _intercept_call
raise new_ex from None
RuntimeError: An error occurred in the server while evaluating the Scheme expression

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
File "/home/afj/shared/pyFluent/codeDir//main.py", line 75, in
s.setup_case(inputs)
File "/home/afj/shared/pyFluent/codeDir/sim.py", line 14, in setup_case
solver = pyfluent.launch_fluent(precision='double', processor_count=inputs['numCPU'], mode='solver', ui_mode=inputs['uiMode'], py=True, product_version=r'25.1',)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/afj/shared/pyFluent/venv/lib/python3.11/site-packages/ansys/fluent/core/utils/deprecate.py", line 73, in wrapper
return decorated(*args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/afj/shared/pyFluent/venv/lib/python3.11/site-packages/deprecated/classic.py", line 199, in wrapper_function
return wrapped_(*args_, **kwargs_)
^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/afj/shared/pyFluent/venv/lib/python3.11/site-packages/ansys/fluent/core/utils/deprecate.py", line 118, in wrapper
return func(*args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^
File "/home/afj/shared/pyFluent/venv/lib/python3.11/site-packages/ansys/fluent/core/utils/deprecate.py", line 118, in wrapper
return func(*args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^
File "/home/afj/shared/pyFluent/venv/lib/python3.11/site-packages/ansys/fluent/core/launcher/launcher.py", line 355, in launch_fluent
return launcher()
^^^^^^^^^^
File "/home/afj/shared/pyFluent/venv/lib/python3.11/site-packages/ansys/fluent/core/launcher/standalone_launcher.py", line 323, in call
raise LaunchFluentError(self._launch_cmd) from ex
ansys.fluent.core.launcher.error_handler.LaunchFluentError:
Fluent Launch command: /opt/Software/corvid/ansys/v251/fluent/bin/fluent 3ddp -py -t4 -sifile=/tmp/serverinfo-kbzdnmqi.txt -nm

💻 Which operating system are you using?

Linux

📀 Which ANSYS version are you using?

Ansys 2025R1

🐍 Which Python version are you using?

3.11

📦 Installed packages

pip show ansys-fluent-core Name: ansys-fluent-core Version: 0.34.2 Summary: PyFluent provides Pythonic access to Ansys Fluent. Home-page: Author: Author-email: "ANSYS, Inc." <pyansys.core@ansys.com>

[prmukherj]

pyfluent.FLUENT_AUTOMATIC_TRANSCRIPT=True, please use this to get the Fluent side transcript to check what's going wrong. Please attach the transcript with this issue.

[abhi-bmi]

cat fluent-20250916-233305-2655164.trn
Auto-Transcript Start Time: 23:33:05, 16 Sep 2025
Current Directory: "/home/afj/shared/pyFluent/testDir"
Running DatamodelService (regular, validated version).
Information: The server has started and is running.
/opt/Software/corvid/ansys/v251/fluent/fluent25.1.0/bin/fluent -r25.1.0 3ddp -pdefault -host -t2 -mpi=intel -path/opt/Software/corvid/ansys/v251/fluent -ssh -cx corvidpost2.cust.loc:37259:32801

Error: There is no active application.
Error Object: (inquire-build-time)

---

WARNING:Found KMP_AFFINITY=none setting in the env

---

Starting /opt/Software/corvid/ansys/v251/fluent/fluent25.1.0/lnamd64/3ddp_host/fluent.25.1.0 host -cx corvidpost2.cust.loc:37259:32801 "(list (rpsetvar (QUOTE parallel/function) "fluent 3ddp -flux -node -r25.1.0 -t2 -pdefault -mpi=intel -ssh") (rpsetvar (QUOTE parallel/rhost) "") (rpsetvar (QUOTE parallel/ruser) "") (rpsetvar (QUOTE parallel/nprocs_string) "2") (rpsetvar (QUOTE parallel/auto-spawn?) #t) (rpsetvar (QUOTE parallel/trace-level) 0) (rpsetvar (QUOTE parallel/remote-shell) 1) (rpsetvar (QUOTE parallel/path) "/opt/Software/corvid/ansys/v251/fluent") (rpsetvar (QUOTE parallel/hostsfile) "") (rpsetvar (QUOTE gpuapp/devices) ""))"

          Welcome to ANSYS Fluent 2025 R1.02

          Copyright 1987-2025 ANSYS, Inc. All Rights Reserved.
          Unauthorized use, distribution or duplication is prohibited.
          This product is subject to U.S. laws governing export and re-export.
          For full Legal Notice, see documentation.

Build Time: Jan 09 2025 12:07:36 EST Build Id: 10211

Connected License Server List: ****@ansys-lm1 // edited license for confidentiality

---

Info: Your license enables 4-way parallel execution.
For faster simulations, please start the application with the appropriate parallel options.

---

Host spawning Node 0 on machine "corvidpost2.cust.loc" (unix).
/opt/Software/corvid/ansys/v251/fluent/fluent25.1.0/bin/fluent -r25.1.0 3ddp -flux -node -t2 -pdefault -mpi=intel -ssh -mport 10.214.168.22:10.214.168.22:39227:0

---

WARNING:Found KMP_AFFINITY=none setting in the env

---

Starting /opt/Software/corvid/ansys/v251/fluent/fluent25.1.0/multiport/mpi/lnamd64/intel2021/bin/mpirun -f /tmp/fluent-appfile.afj_abiradar.2656197 -genv I_MPI_FABRICS shm -genv FLUENT_ARCH lnamd64 -genv I_MPI_DEBUG 0 -genv I_MPI_ADJUST_GATHERV 3 -genv I_MPI_ADJUST_ALLREDUCE 2 -genv I_MPI_PLATFORM auto -genv PYTHONHOME /opt/Software/corvid/ansys/v251/fluent/fluent25.1.0/../../commonfiles/CPython/3_10/linx64/Release/python -genv FLUENT_PROD_DIR /opt/Software/corvid/ansys/v251/fluent/fluent25.1.0 -genv FLUENT_AFFINITY 0 -genv I_MPI_PIN enable -n 2 /opt/Software/corvid/ansys/v251/fluent/fluent25.1.0/lnamd64/3ddp_node/fluent_mpi.25.1.0 node -mpiw intel -pic shmem -mport 10.214.168.22:10.214.168.22:39227:0

---

ID Hostname Core O.S. PID Vendor

n0-1 corvidpost2.cust.loc 2/128 Linux-64 2656279-2656280 Intel(R) Xeon(R) Gold 6328H
host corvidpost2.cust.loc Linux-64 2655743 Intel(R) Xeon(R) Gold 6328H

MPI Option Selected: intel
Selected system interconnect: shared-memory

Cleanup script file is /home/afj/shared/pyFluent/testDir/cleanup-fluent-corvidpost2.cust.loc-2655743.sh

Warning:
Software rasterizer found, hardware acceleration will be disabled.

In the absence of hardware-accelerated drivers, the performance of all graphics operations will be severely affected. Make sure you have a supported graphics card, latest graphics driver, and a supported remote visualization tool with direct server-side rendering enabled. If you feel your system meets these requirements, try forcing the accelerated driver by using the command line flag (-driver ) or setting the HOOPS_PICTURE environment variable. Refer to the documentation for more details.

Graphics driver currently in use: x11

Above is the out put from transcript file.

Currently, when we try to launch Fluent using

solver = pyfluent.launch_fluent()

we encounter an error.

As a workaround, we are launching Fluent directly from the terminal with the following command:

/opt/Software/corvid/ansys/v251/fluent/bin/fluent 3ddp -py -t4 -sifile=/tmp/serverinfo-kbzdnmqi.txt -nm

After starting Fluent this way, we connect to it from PyFluent using the server info file:

solver = pyfluent.connect_to_fluent(server_info_file_name=sifile)

This approach works for us. However, we are still facing issues when trying to use launch_fluent with the GUI option.

[abhi-bmi]

If any updates in this issue Please connect with below peoples : aabijwar@burnsmcd.com , amlefebvre2@burnsmcd.com , biradarabhi7@gmail.com