Failed to solve extension dependency

[Barzol]

Hi everyone, i'm trying to install Ocean Sim. When I try to activate the extension on IsaacSim, it fails and report the message "Failed to solve extension dependency". Can you help me fix it?

[haoyuma2002814]

Can you copy and paste the error shown in the terminal?

[Barzol]

[101.234s] [ext: OceanSim-1.0.0] startup
2025-05-09 12:03:26 [101,152ms] [Warning] [omni.isaac.ui.menu] omni.isaac.ui has been deprecated in favor of isaacsim.gui.components. Please update your code accordingly.
2025-05-09 12:03:26 [101,227ms] [Error] [omni.ext._impl._internal] Failed to import python module isaacsim.oceansim.modules.SensorExample_python from c:\isaacsim\extsuser\OceanSim. Error: (unicode error) 'unicodeescape' codec can't decode bytes in position 2-3: truncated \UXXXXXXXX escape (c:/isaacsim/extsuser/OceanSim/isaacsim/oceansim/utils/assets_utils.py, line 3). Traceback:
Traceback (most recent call last):
File "c:\isaacsim/kit/kernel/py\omni\ext_impl_internal.py", line 187, in custom_importer
return import_public(ext_module.path, ext_module.name, reload_enabled)
File "c:\isaacsim/kit/kernel/py\carb\profiler_init.py", line 99, in wrapper
r = f(*args, **kwds)
File "c:\isaacsim/kit/kernel/py\omni\ext_impl_internal.py", line 94, in import_public
module = import_module(module_name)
File "c:\isaacsim/kit/kernel/py\carb\profiler_init.py", line 99, in wrapper
r = f(*args, **kwds)
File "c:\isaacsim/kit/kernel/py\omni\ext_impl\custom_importer.py", line 76, in import_module
return importlib.import_module(name)
File "c:\isaacsim\kit\python\lib\importlib_init.py", line 126, in import_module
return _bootstrap._gcd_import(name[level:], package, level)
File "", line 1050, in _gcd_import
File "", line 1027, in _find_and_load
File "", line 1006, in _find_and_load_unlocked
File "", line 688, in _load_unlocked
File "", line 883, in exec_module
File "", line 241, in _call_with_frames_removed
File "c:/isaacsim/extsuser/OceanSim/isaacsim/oceansim/modules/SensorExample_python/init.py", line 9, in
from .extension import *
File "c:/isaacsim/extsuser/OceanSim/isaacsim/oceansim/modules/SensorExample_python/extension.py", line 27, in
from .ui_builder import UIBuilder
File "c:/isaacsim/extsuser/OceanSim/isaacsim/oceansim/modules/SensorExample_python/ui_builder.py", line 24, in
from isaacsim.oceansim.utils.assets_utils import get_oceansim_assets_path
File "c:/isaacsim/extsuser/OceanSim/isaacsim/oceansim/utils/assets_utils.py", line 3
return "c:\Users\Maria\Desktop\Tesi\OceanSim_assets"
^
SyntaxError: (unicode error) 'unicodeescape' codec can't decode bytes in position 2-3: truncated \UXXXXXXXX escape

2025-05-09 12:03:26 [101,231ms] [Error] [carb.scripting-python.plugin] Exception: Extension python module: 'isaacsim.oceansim.modules.SensorExample_python' in 'c:\isaacsim\extsuser\OceanSim' failed to load.

At:
c:\isaacsim/kit/kernel/py\omni\ext_impl_internal.py(213): startup
c:\isaacsim/kit/kernel/py\omni\ext_impl_internal.py(328): startup_extension
PythonExtension.cpp::startup()(2):
c:/isaacsim/extscache/omni.kit.window.extensions-1.4.25+d02c707b/omni/kit/window/extensions/ext_commands.py(33): do
c:/isaacsim/extscache/omni.kit.commands-1.4.9+d02c707b.wx64.r.cp310/omni/kit/undo/undo.py(81): execute
c:/isaacsim/extscache/omni.kit.commands-1.4.9+d02c707b.wx64.r.cp310/omni/kit/commands/command.py(463): execute
c:/isaacsim/extscache/omni.kit.window.extensions-1.4.25+d02c707b/omni/kit/window/extensions/common.py(509): toggle_self
c:\isaacsim\kit\python\lib\asyncio\events.py(80): _run
c:\isaacsim\kit\python\lib\asyncio\base_events.py(1909): _run_once
c:/isaacsim/kit/extscore/omni.kit.async_engine/omni/kit/async_engine/async_engine.py(197): run_once
c:/isaacsim/kit/extscore/omni.kit.async_engine/omni/kit/async_engine/async_engine.py(263):

2025-05-09 12:03:26 [101,231ms] [Error] [omni.ext.plugin] [ext: OceanSim-1.0.0] Failed to startup python extension.
2025-05-09 12:03:27 [101,612ms] [Error] [omni.kit.app._impl] [py stderr]: Traceback (most recent call last):
2025-05-09 12:03:27 [101,614ms] [Error] [omni.kit.app._impl] [py stderr]: File "c:/isaacsim/extscache/omni.graph-1.140.2+d02c707b.wx64.r.cp310/omni/graph/core/_impl/_registration/extension_management.py", line 150, in extension_management_factory
2025-05-09 12:03:27 [101,625ms] [Error] [omni.kit.app._impl] [py stderr]: main_module = sys.modules[module_name]
2025-05-09 12:03:27 [101,626ms] [Error] [omni.kit.app._impl] [py stderr]: KeyError: 'isaacsim.oceansim.modules.SensorExample_python'
2025-05-09 12:03:27 [101,627ms] [Error] [omni.kit.app._impl] [py stderr]:
During handling of the above exception, another exception occurred:

2025-05-09 12:03:27 [101,627ms] [Error] [omni.kit.app._impl] [py stderr]: Traceback (most recent call last):
2025-05-09 12:03:27 [101,627ms] [Error] [omni.kit.app._impl] [py stderr]: File "c:/isaacsim/extscache/omni.graph-1.140.2+d02c707b.wx64.r.cp310/omni/graph/core/_impl/extension.py", line 197, in __register_nodes
2025-05-09 12:03:27 [101,638ms] [Error] [omni.kit.app._impl] [py stderr]: new_registration = og.PythonNodeRegistration(ext_name, module_name, ext_path, autonode_config)
2025-05-09 12:03:27 [101,638ms] [Error] [omni.kit.app._impl] [py stderr]: File "c:/isaacsim/extscache/omni.graph-1.140.2+d02c707b.wx64.r.cp310/omni/graph/core/_impl/registration.py", line 41, in init
2025-05-09 12:03:27 [101,646ms] [Error] [omni.kit.app._impl] [py stderr]: self.__deregistration_methods = register_python_ogn(ext_name, module_name, ext_path)
2025-05-09 12:03:27 [101,647ms] [Error] [omni.kit.app.impl] [py stderr]: File "c:\isaacsim/kit/kernel/py\carb\profiler_init.py", line 99, in wrapper
2025-05-09 12:03:27 [101,648ms] [Error] [omni.kit.app._impl] [py stderr]: r = f(*args, **kwds)
2025-05-09 12:03:27 [101,648ms] [Error] [omni.kit.app._impl] [py stderr]: File "c:/isaacsim/extscache/omni.graph-1.140.2+d02c707b.wx64.r.cp310/omni/graph/core/_impl/_registration/register_python_ogn.py", line 76, in register_python_ogn
2025-05-09 12:03:27 [101,657ms] [Error] [omni.kit.app._impl] [py stderr]: ext_contents = extension_management_factory(ext_name, module_name, Path(ext_path_name))
2025-05-09 12:03:27 [101,658ms] [Error] [omni.kit.app._impl] [py stderr]: File "c:/isaacsim/extscache/omni.graph-1.140.2+d02c707b.wx64.r.cp310/omni/graph/core/_impl/_registration/extension_management.py", line 153, in extension_management_factory
2025-05-09 12:03:27 [101,659ms] [Error] [omni.kit.app._impl] [py stderr]: main_module = import_module(module_name)
2025-05-09 12:03:27 [101,659ms] [Error] [omni.kit.app.impl] [py stderr]: File "c:\isaacsim\kit\python\lib\importlib_init.py", line 126, in import_module
2025-05-09 12:03:27 [101,660ms] [Error] [omni.kit.app._impl] [py stderr]: return _bootstrap._gcd_import(name[level:], package, level)
2025-05-09 12:03:27 [101,660ms] [Error] [omni.kit.app._impl] [py stderr]: File "", line 1050, in _gcd_import
2025-05-09 12:03:27 [101,662ms] [Error] [omni.kit.app._impl] [py stderr]: File "", line 1027, in _find_and_load
2025-05-09 12:03:27 [101,663ms] [Error] [omni.kit.app._impl] [py stderr]: File "", line 1006, in _find_and_load_unlocked
2025-05-09 12:03:27 [101,665ms] [Error] [omni.kit.app._impl] [py stderr]: File "", line 688, in _load_unlocked
2025-05-09 12:03:27 [101,666ms] [Error] [omni.kit.app._impl] [py stderr]: File "", line 883, in exec_module
2025-05-09 12:03:27 [101,667ms] [Error] [omni.kit.app._impl] [py stderr]: File "", line 241, in _call_with_frames_removed
2025-05-09 12:03:27 [101,669ms] [Error] [omni.kit.app._impl] [py stderr]: File "c:/isaacsim/extsuser/OceanSim/isaacsim/oceansim/modules/SensorExample_python/init.py", line 9, in
2025-05-09 12:03:27 [101,670ms] [Error] [omni.kit.app._impl] [py stderr]: from .extension import *
2025-05-09 12:03:27 [101,671ms] [Error] [omni.kit.app._impl] [py stderr]: File "c:/isaacsim/extsuser/OceanSim/isaacsim/oceansim/modules/SensorExample_python/extension.py", line 27, in
2025-05-09 12:03:27 [101,671ms] [Error] [omni.kit.app._impl] [py stderr]: from .ui_builder import UIBuilder
2025-05-09 12:03:27 [101,672ms] [Error] [omni.kit.app._impl] [py stderr]: File "c:/isaacsim/extsuser/OceanSim/isaacsim/oceansim/modules/SensorExample_python/ui_builder.py", line 24, in
2025-05-09 12:03:27 [101,672ms] [Error] [omni.kit.app._impl] [py stderr]: from isaacsim.oceansim.utils.assets_utils import get_oceansim_assets_path
2025-05-09 12:03:27 [101,672ms] [Error] [omni.kit.app._impl] [py stderr]: File "c:/isaacsim/extsuser/OceanSim/isaacsim/oceansim/utils/assets_utils.py", line 3
2025-05-09 12:03:27 [101,673ms] [Error] [omni.kit.app._impl] [py stderr]: return "c:\Users\Maria\Desktop\Tesi\OceanSim_assets"
2025-05-09 12:03:27 [101,673ms] [Error] [omni.kit.app._impl] [py stderr]: ^
2025-05-09 12:03:27 [101,674ms] [Error] [omni.kit.app._impl] [py stderr]: SyntaxError: (unicode error) 'unicodeescape' codec can't decode bytes in position 2-3: truncated \UXXXXXXXX escape
[101.990s] [ext: OceanSim-1.0.0] shutdown

[haoyuma2002814]

The path that you input and links to downloaded assets in get_oceansim_assets_path() is the culprit. It seems to be contains string that can not be identified.

SyntaxError: (unicode error) 'unicodeescape' codec can't decode bytes in position 2-3: truncated \UXXXXXXXX escape

Since you are using a windows system, I would recommend checking the convention of how to properly key in the path\URL so that isaac sim can load the assets. Maybe check symbol : in "c:\Users\Maria\Desktop\Tesi\OceanSim_assets" first.

[Barzol]

I changed the path, I think the problem was that there were 2 folders called "Ocean_assets". Thank you very much!

[xxxfry22]

I also encountered the same problem, could you tell me how to solve it?

[Barzol]

idk, for me it was that i had 2 "Ocean_assets" folders

[xxxfry22]

2025-06-22 08:23:15 [346,274ms] [Error] [omni.ext._impl._internal] Failed to import python module isaacsim.oceansim.modules.SensorExample_python from d:\isaacsim\extsuser\OceanSim. Error: stat: path should be string, bytes, os.PathLike or integer, not NoneType. Traceback:
Traceback (most recent call last):
File "d:\isaacsim/kit/kernel/py\omni\ext_impl_internal.py", line 187, in custom_importer
return import_public(ext_module.path, ext_module.name, reload_enabled)
File "d:\isaacsim/kit/kernel/py\carb\profiler_init.py", line 99, in wrapper
r = f(*args, **kwds)
File "d:\isaacsim/kit/kernel/py\omni\ext_impl_internal.py", line 94, in import_public
module = import_module(module_name)
File "d:\isaacsim/kit/kernel/py\carb\profiler_init.py", line 99, in wrapper
r = f(*args, **kwds)
File "d:\isaacsim/kit/kernel/py\omni\ext_impl\custom_importer.py", line 76, in import_module
return importlib.import_module(name)
File "d:\isaacsim\kit\python\lib\importlib_init.py", line 126, in import_module
return _bootstrap._gcd_import(name[level:], package, level)
File "", line 1050, in _gcd_import
File "", line 1027, in _find_and_load
File "", line 1006, in _find_and_load_unlocked
File "", line 688, in _load_unlocked
File "", line 883, in exec_module
File "", line 241, in _call_with_frames_removed
File "d:/isaacsim/extsuser/OceanSim/isaacsim/oceansim/modules/SensorExample_python/init.py", line 9, in
from .extension import *
File "d:/isaacsim/extsuser/OceanSim/isaacsim/oceansim/modules/SensorExample_python/extension.py", line 27, in
from .ui_builder import UIBuilder
File "d:/isaacsim/extsuser/OceanSim/isaacsim/oceansim/modules/SensorExample_python/ui_builder.py", line 24, in
from isaacsim.oceansim.utils.assets_utils import get_oceansim_assets_path
File "d:/isaacsim/extsuser/OceanSim/isaacsim/oceansim/utils/assets_utils.py", line 41, in
get_oceansim_assets_path()
File "d:/isaacsim/extsuser/OceanSim/isaacsim/oceansim/utils/assets_utils.py", line 33, in get_oceansim_assets_path
if not os.path.isdir(asset_path):
File "d:\isaacsim\kit\python\lib\genericpath.py", line 42, in isdir
st = os.stat(s)
TypeError: stat: path should be string, bytes, os.PathLike or integer, not NoneType

2025-06-22 08:23:15 [346,275ms] [Error] [carb.scripting-python.plugin] Exception: Extension python module: 'isaacsim.oceansim.modules.SensorExample_python' in 'd:\isaacsim\extsuser\OceanSim' failed to load.

At:
d:\isaacsim/kit/kernel/py\omni\ext_impl_internal.py(213): startup
d:\isaacsim/kit/kernel/py\omni\ext_impl_internal.py(328): startup_extension
PythonExtension.cpp::startup()(2):
d:/isaacsim/extscache/omni.kit.window.extensions-1.4.25+d02c707b/omni/kit/window/extensions/ext_commands.py(33): do
d:/isaacsim/extscache/omni.kit.commands-1.4.9+d02c707b.wx64.r.cp310/omni/kit/undo/undo.py(81): execute
d:/isaacsim/extscache/omni.kit.commands-1.4.9+d02c707b.wx64.r.cp310/omni/kit/commands/command.py(463): execute
d:/isaacsim/extscache/omni.kit.window.extensions-1.4.25+d02c707b/omni/kit/window/extensions/common.py(509): toggle_self
d:\isaacsim\kit\python\lib\asyncio\events.py(80): _run
d:\isaacsim\kit\python\lib\asyncio\base_events.py(1909): _run_once
d:/isaacsim/kit/extscore/omni.kit.async_engine/omni/kit/async_engine/async_engine.py(197): run_once
d:/isaacsim/kit/extscore/omni.kit.async_engine/omni/kit/async_engine/async_engine.py(263):

2025-06-22 08:23:15 [346,276ms] [Error] [omni.ext.plugin] [ext: OceanSim-1.0.0] Failed to startup python extension.
2025-06-22 08:23:15 [346,526ms] [Error] [omni.kit.app._impl] [py stderr]: Traceback (most recent call last):
2025-06-22 08:23:15 [346,527ms] [Error] [omni.kit.app._impl] [py stderr]: File "d:/isaacsim/extscache/omni.graph-1.140.2+d02c707b.wx64.r.cp310/omni/graph/core/_impl/_registration/extension_management.py", line 150, in extension_management_factory
2025-06-22 08:23:15 [346,527ms] [Error] [omni.kit.app._impl] [py stderr]: main_module = sys.modules[module_name]
2025-06-22 08:23:15 [346,528ms] [Error] [omni.kit.app._impl] [py stderr]: KeyError: 'isaacsim.oceansim.modules.SensorExample_python'
2025-06-22 08:23:15 [346,528ms] [Error] [omni.kit.app._impl] [py stderr]:
During handling of the above exception, another exception occurred:

2025-06-22 08:23:15 [346,528ms] [Error] [omni.kit.app._impl] [py stderr]: Traceback (most recent call last):
2025-06-22 08:23:15 [346,529ms] [Error] [omni.kit.app._impl] [py stderr]: File "d:/isaacsim/extscache/omni.graph-1.140.2+d02c707b.wx64.r.cp310/omni/graph/core/_impl/extension.py", line 197, in __register_nodes
2025-06-22 08:23:15 [346,529ms] [Error] [omni.kit.app._impl] [py stderr]: new_registration = og.PythonNodeRegistration(ext_name, module_name, ext_path, autonode_config)
2025-06-22 08:23:15 [346,530ms] [Error] [omni.kit.app._impl] [py stderr]: File "d:/isaacsim/extscache/omni.graph-1.140.2+d02c707b.wx64.r.cp310/omni/graph/core/_impl/registration.py", line 41, in init
2025-06-22 08:23:15 [346,530ms] [Error] [omni.kit.app._impl] [py stderr]: self.__deregistration_methods = register_python_ogn(ext_name, module_name, ext_path)
2025-06-22 08:23:15 [346,530ms] [Error] [omni.kit.app.impl] [py stderr]: File "d:\isaacsim/kit/kernel/py\carb\profiler_init.py", line 99, in wrapper
2025-06-22 08:23:15 [346,531ms] [Error] [omni.kit.app._impl] [py stderr]: r = f(*args, **kwds)
2025-06-22 08:23:15 [346,531ms] [Error] [omni.kit.app._impl] [py stderr]: File "d:/isaacsim/extscache/omni.graph-1.140.2+d02c707b.wx64.r.cp310/omni/graph/core/_impl/_registration/register_python_ogn.py", line 76, in register_python_ogn
2025-06-22 08:23:15 [346,531ms] [Error] [omni.kit.app._impl] [py stderr]: ext_contents = extension_management_factory(ext_name, module_name, Path(ext_path_name))
2025-06-22 08:23:15 [346,531ms] [Error] [omni.kit.app._impl] [py stderr]: File "d:/isaacsim/extscache/omni.graph-1.140.2+d02c707b.wx64.r.cp310/omni/graph/core/_impl/_registration/extension_management.py", line 153, in extension_management_factory
2025-06-22 08:23:15 [346,532ms] [Error] [omni.kit.app._impl] [py stderr]: main_module = import_module(module_name)
2025-06-22 08:23:15 [346,532ms] [Error] [omni.kit.app.impl] [py stderr]: File "d:\isaacsim\kit\python\lib\importlib_init.py", line 126, in import_module
2025-06-22 08:23:15 [346,533ms] [Error] [omni.kit.app._impl] [py stderr]: return _bootstrap._gcd_import(name[level:], package, level)
2025-06-22 08:23:15 [346,533ms] [Error] [omni.kit.app._impl] [py stderr]: File "", line 1050, in _gcd_import
2025-06-22 08:23:15 [346,533ms] [Error] [omni.kit.app._impl] [py stderr]: File "", line 1027, in _find_and_load
2025-06-22 08:23:15 [346,534ms] [Error] [omni.kit.app._impl] [py stderr]: File "", line 1006, in _find_and_load_unlocked
2025-06-22 08:23:15 [346,534ms] [Error] [omni.kit.app._impl] [py stderr]: File "", line 688, in _load_unlocked
2025-06-22 08:23:15 [346,534ms] [Error] [omni.kit.app._impl] [py stderr]: File "", line 883, in exec_module
2025-06-22 08:23:15 [346,535ms] [Error] [omni.kit.app._impl] [py stderr]: File "", line 241, in _call_with_frames_removed
2025-06-22 08:23:15 [346,535ms] [Error] [omni.kit.app._impl] [py stderr]: File "d:/isaacsim/extsuser/OceanSim/isaacsim/oceansim/modules/SensorExample_python/init.py", line 9, in
2025-06-22 08:23:15 [346,536ms] [Error] [omni.kit.app._impl] [py stderr]: from .extension import *
2025-06-22 08:23:15 [346,537ms] [Error] [omni.kit.app._impl] [py stderr]: File "d:/isaacsim/extsuser/OceanSim/isaacsim/oceansim/modules/SensorExample_python/extension.py", line 27, in
2025-06-22 08:23:15 [346,537ms] [Error] [omni.kit.app._impl] [py stderr]: from .ui_builder import UIBuilder
2025-06-22 08:23:15 [346,537ms] [Error] [omni.kit.app._impl] [py stderr]: File "d:/isaacsim/extsuser/OceanSim/isaacsim/oceansim/modules/SensorExample_python/ui_builder.py", line 24, in
2025-06-22 08:23:15 [346,538ms] [Error] [omni.kit.app._impl] [py stderr]: from isaacsim.oceansim.utils.assets_utils import get_oceansim_assets_path
2025-06-22 08:23:15 [346,538ms] [Error] [omni.kit.app._impl] [py stderr]: File "d:/isaacsim/extsuser/OceanSim/isaacsim/oceansim/utils/assets_utils.py", line 41, in
2025-06-22 08:23:15 [346,538ms] [Error] [omni.kit.app._impl] [py stderr]: get_oceansim_assets_path()
2025-06-22 08:23:15 [346,539ms] [Error] [omni.kit.app._impl] [py stderr]: File "d:/isaacsim/extsuser/OceanSim/isaacsim/oceansim/utils/assets_utils.py", line 33, in get_oceansim_assets_path
2025-06-22 08:23:15 [346,539ms] [Error] [omni.kit.app._impl] [py stderr]: if not os.path.isdir(asset_path):
2025-06-22 08:23:15 [346,539ms] [Error] [omni.kit.app._impl] [py stderr]: File "d:\isaacsim\kit\python\lib\genericpath.py", line 42, in isdir
2025-06-22 08:23:15 [346,540ms] [Error] [omni.kit.app._impl] [py stderr]: st = os.stat(s)
2025-06-22 08:23:15 [346,540ms] [Error] [omni.kit.app._impl] [py stderr]: TypeError: stat: path should be string, bytes, os.PathLike or integer, not NoneType

[haoyuma2002814]

Hi.

Can you check again on the asset_path variable.

The error comes from
if not os.path.isdir(asset_path):
for which the asset_path is not defined properly.

Can you check if you have set proper path to the assets when you install OceanSim?

If it still doesn't solve your problem,
please describe how you do this step during your installation:

cd /path/to/OceanSim
python3 config/register_asset_path.py /path/to/OceanSim_assets

Thank you.

[xxxfry22]

Thank you for your help. The problem has been solved. The problem was that the python interpreter of Isaac sim was not used correctly.