location : unknown location :-1 ERROR

Hi when i try export my blender project as gITF file or click sneak peek, i am getting this error:

Traceback (most recent call last):
File “C:\Users\mehme\AppData\Roaming\Blender Foundation\Blender\2.82\scripts\addons\verge3d\custom_ui.py”, line 623, in execute
filepath=join(prev_dir, “sneak_peek.gltf”), export_sneak_peek = True)
File “C:\Program Files\Blender Foundation\Blender 2.82\2.82\scripts\modules\bpy\ops.py”, line 201, in __call__
ret = op_call(self.idname_py(), None, kw)
RuntimeError: Error: Traceback (most recent call last):
File “C:\Users\mehme\AppData\Roaming\Blender Foundation\Blender\2.82\scripts\addons\verge3d\__init__.py”, line 143, in execute
return gltf2_export.save(self, context, exportSettings)
File “C:\Users\mehme\AppData\Roaming\Blender Foundation\Blender\2.82\scripts\addons\verge3d\gltf2_export.py”, line 121, in save
generateGLTF(operator, context, exportSettings, glTF)
File “C:\Users\mehme\AppData\Roaming\Blender Foundation\Blender\2.82\scripts\addons\verge3d\gltf2_generate.py”, line 3129, in generateGLTF
generateNodes(operator, context, exportSettings, glTF)
File “C:\Users\mehme\AppData\Roaming\Blender Foundation\Blender\2.82\scripts\addons\verge3d\gltf2_generate.py”, line 1998, in generateNodes
node = generateNodeInstance(operator, context, exportSettings, glTF, bl_object)
File “C:\Users\mehme\AppData\Roaming\Blender Foundation\Blender\2.82\scripts\addons\verge3d\gltf2_generate.py”, line 1835, in generateNodeInstance
mesh = getMeshIndexDupliCheck(operator, context, exportSettings, glTF, bl_object)
File “C:\Users\mehme\AppData\Roaming\Blender Foundation\Blender\2.82\scripts\addons\verge3d\gltf2_generate.py”, line 1807, in getMeshIndexDupliCheck
bl_object)
File “C:\Users\mehme\AppData\Roaming\Blender Foundation\Blender\2.82\scripts\addons\verge3d\gltf2_generate.py”, line 1760, in generateDuplicateMesh
else gltf.getMaterialIndex(glTF, blender_material_slot.material.name))
IndexError: list index out of range

location: C:\Program Files\Blender Foundation\Blender 2.82\2.82\scripts\modules\bpy\ops.py:201

location: <unknown location>:-1

Traceback (most recent call last):
File “C:\Users\mehme\AppData\Roaming\Blender Foundation\Blender\2.82\scripts\addons\verge3d\custom_ui.py”, line 623, in execute
filepath=join(prev_dir, “sneak_peek.gltf”), export_sneak_peek = True)
File “C:\Program Files\Blender Foundation\Blender 2.82\2.82\scripts\modules\bpy\ops.py”, line 201, in __call__
ret = op_call(self.idname_py(), None, kw)
RuntimeError: Error: Traceback (most recent call last):
File “C:\Users\mehme\AppData\Roaming\Blender Foundation\Blender\2.82\scripts\addons\verge3d\__init__.py”, line 143, in execute
return gltf2_export.save(self, context, exportSettings)
File “C:\Users\mehme\AppData\Roaming\Blender Foundation\Blender\2.82\scripts\addons\verge3d\gltf2_export.py”, line 121, in save
generateGLTF(operator, context, exportSettings, glTF)
File “C:\Users\mehme\AppData\Roaming\Blender Foundation\Blender\2.82\scripts\addons\verge3d\gltf2_generate.py”, line 3129, in generateGLTF
generateNodes(operator, context, exportSettings, glTF)
File “C:\Users\mehme\AppData\Roaming\Blender Foundation\Blender\2.82\scripts\addons\verge3d\gltf2_generate.py”, line 1998, in generateNodes
node = generateNodeInstance(operator, context, exportSettings, glTF, bl_object)
File “C:\Users\mehme\AppData\Roaming\Blender Foundation\Blender\2.82\scripts\addons\verge3d\gltf2_generate.py”, line 1835, in generateNodeInstance
mesh = getMeshIndexDupliCheck(operator, context, exportSettings, glTF, bl_object)
File “C:\Users\mehme\AppData\Roaming\Blender Foundation\Blender\2.82\scripts\addons\verge3d\gltf2_generate.py”, line 1807, in getMeshIndexDupliCheck
bl_object)
File “C:\Users\mehme\AppData\Roaming\Blender Foundation\Blender\2.82\scripts\addons\verge3d\gltf2_generate.py”, line 1760, in generateDuplicateMesh
else gltf.getMaterialIndex(glTF, blender_material_slot.material.name))
IndexError: list index out of range

location: C:\Program Files\Blender Foundation\Blender 2.82\2.82\scripts\modules\bpy\ops.py:201

location: <unknown location>:-1

Do you have any idea?