Blender plugin randomly fails to load previously added materials

When loading an existing blender file that contains imported materials, one or more of the materials randomly fail to load. For example:

Substance 3D in Blender: INFO - Shader Presets initialized...
Substance 3D in Blender: INFO - Scene Substances loaded correctly
Substance 3D in Blender: INFO - Plugin initialization...
No Instance(s) Available.
Substance 3D in Blender: INFO - Toolkit Initialized...
Substance 3D in Blender: INFO - Toolkit version [1.4.5]...
Substance 3D in Blender: INFO - [Code_Response.success] Server already running...
Substance 3D in Blender: INFO - Server Port [51649]
Substance 3D in Blender: INFO - Scene Substances loaded correctly
Info: Substance 3D in Blender: SRE Initialized sucessfully in [0.809] seconds

Substance 3D in Blender: ERROR - Exception - Unknown Error while setting parameter visibility
Substance 3D in Blender: ERROR - TRACEBACK:

Traceback (most recent call last):
File "C:\Users\Thor Ekle\AppData\Roaming\Blender Foundation\Blender\3.3\scripts\addons\Substance3DInBlender\sbsar\async_ops.py", line 407, in _reload_sbsar_data
_outputs_class.from_json(_data)
File "C:\Users\Thor Ekle\AppData\Roaming\Blender Foundation\Blender\3.3\scripts\addons\Substance3DInBlender\factory\sbsar.py", line 76, in _output_from_json
setattr(self, _key + Code_OutParms.bitdepth.value, _output["shader_bitdepth"])
AttributeError: Writing to ID classes in this context is not allowed: Scene, Scene datablock, error setting SUBSTANCE_SGO_9450933C-129F-43A9-8342-2B80A442B6BA.roughness_bitdepth

Substance 3D in Blender: ERROR - Exception - Rest Ignore Connection error: http://127.0.0.1:41646/v1/sbsar/3221FCF7-6551-4ED3-9AA4-BA40CF2B1B1D/output/2360350290
Substance 3D in Blender: ERROR - [(<Code_Response.rest_ignore_connection_error: -17>, 'http://127.0.0.1:41646/v1/sbsar/3221FCF7-6551-4ED3-9AA4-BA40CF2B1B1D/output/2360350290')] Threaded request fail: http://127.0.0.1:41646/v1/sbsar/3221FCF7-6551-4ED3-9AA4-BA40CF2B1B1D/output/2360350290
Substance 3D in Blender: ERROR - Exception - Rest Ignore Connection error: http://127.0.0.1:41646/v1/sbsar/C6DF02BC-3C54-44BF-8C21-F3B6BC3B70AE/output/2804012286
Substance 3D in Blender: ERROR - [(<Code_Response.rest_ignore_connection_error: -17>, 'http://127.0.0.1:41646/v1/sbsar/C6DF02BC-3C54-44BF-8C21-F3B6BC3B70AE/output/2804012286')] Threaded request fail: http://127.0.0.1:41646/v1/sbsar/C6DF02BC-3C54-44BF-8C21-F3B6BC3B70AE/output/2804012286
Info: Substance 3D in Blender: Substance [flat_limestone_rock_formation_02] was reloaded correctly

Info: Substance 3D in Blender: Substance [skyros_marble] was reloaded correctly

Info: Substance 3D in Blender: Substance [beech_toast_wood_varnished] was reloaded correctly

Info: Substance 3D in Blender: Substance [random_terrazzo_inserts] was reloaded correctly

Error: Substance 3D in Blender: An error ocurred while reloading the substance [bark_chips_covered_soil_01]

There doesn't seem to be any rhyme or reason to which materials fail and which load correctly.

Plugin version 1.01, integration tool 1.45, blender, 3.3.1.