problem with saving the file

[Timerlen]

After loading the dxf file it saves it under a different name, but with an error, the file cannot be opened with the new name.
Code:

import ezdxf
doc = ezdxf.readfile("123.dxf")
msp = doc.modelspace()
for e in msp:
if e.dxftype()== 'LINE':
print(e)
doc.saveas('NAMEd1a.dxf')

Error:
Traceback (most recent call last):
File "F:\login\asdasdasdasdasd.py", line 13, in
doc.saveas('NAMEd1a.dxf')
File "F:\login\venv\lib\site-packages\ezdxf\document.py", line 439, in saveas
self.save(encoding=encoding, fmt=fmt)
File "F:\login\venv\lib\site-packages\ezdxf\document.py", line 472, in save
self.write(fp, fmt=fmt)
File "F:\login\venv\lib\site-packages\ezdxf\document.py", line 523, in write
self.export_sections(tagwriter)
File "F:\login\venv\lib\site-packages\ezdxf\document.py", line 544, in export_sections
self.objects.export_dxf(tagwriter)
File "F:\login\venv\lib\site-packages\ezdxf\sections\objects.py", line 57, in export_dxf
self._entity_space.export_dxf(tagwriter)
File "F:\login\venv\lib\site-packages\ezdxf\entitydb.py", line 344, in export_dxf
entity.export_dxf(tagwriter)
File "F:\login\venv\lib\site-packages\ezdxf\entities\dxfentity.py", line 533, in export_dxf
self.export_entity(tagwriter)
File "F:\login\venv\lib\site-packages\ezdxf\entities\material.py", line 251, in export_entity
export_matrix(tagwriter, 43, self.diffuse_mapper_matrix)
File "F:\login\venv\lib\site-packages\ezdxf\entities\material.py", line 41, in export_matrix
for value in matrix.matrix:
AttributeError: 'ezdxf.acc.matrix44.Matrix44' object has no attribute 'matrix'

[mozman]

was fixed in v0.15.1 released 2021-01-15

[Timerlen]

Thank you for your help