ytdl-org/youtube-dl · error · ExtractorError
Unsupported trait kind %d
Error message
Unsupported trait kind %d
What it means
Error "Unsupported trait kind %d" thrown in ytdl-org/youtube-dl.
Source
Thrown at youtube_dl/swfinterp.py:337
value = self.constant_ints[vindex]
elif vkind == 0x04: # Constant_UInt
value = self.constant_uints[vindex]
else:
return {}, None # Ignore silently for now
constants = {self.multinames[trait_name_idx]: value}
elif kind in (0x01, 0x02, 0x03): # Method / Getter / Setter
u30() # disp_id
method_idx = u30()
methods[self.multinames[trait_name_idx]] = method_idx
elif kind == 0x04: # Class
u30() # slot_id
u30() # classi
elif kind == 0x05: # Function
u30() # slot_id
function_idx = u30()
methods[function_idx] = self.multinames[trait_name_idx]
else:
raise ExtractorError('Unsupported trait kind %d' % kind)
if attrs & 0x4 != 0: # Metadata present
metadata_count = u30()
for _c3 in range(metadata_count):
u30() # metadata index
return methods, constants
# Classes
class_count = u30()
classes = []
for class_id in range(class_count):
name_idx = u30()
cname = self.multinames[name_idx]
avm_class = _AVMClass(name_idx, cname)
classes.append(avm_class)
View on GitHub (pinned to 956b8c5855)
Solutions
- Update youtube-dl; the SWF uses a trait kind the interpreter does not support.
When it happens
Trigger: Thrown at youtube_dl/swfinterp.py:337 when the library encounters an invalid state.
Common situations: See trigger scenarios.
AI-assisted analysis of ytdl-org/youtube-dl@956b8c5855 (2026-08-14).
Data as JSON: /api/errors/fa3b1a878e91c5c9.
Report an issue: GitHub.