[SOLVED] error S4Studio.Blender.BlenderException

Hi does anybody know what this error means? Thanks!

imgur.com/ZsmFK5k

The Sims 4 Studio - Version 3.1.5.8

System.AggregateException: One or more errors occurred. ---> S4Studio.Blender.BlenderException:

File "<string>", line 1, in <module>

File "<string>", line 39, in <module>

File "C:\Users\[UserName]\AppData\Roaming\Blender Foundation\Blender\2.70\scripts\addons\s4studio\cas\blender.py", line 122, in save_geom

weight_list[blend_index_map] = min(int(vertex.groups.weight * 255), 255)

ValueError: cannot convert float NaN to integer





at S4Studio.Blender.BlenderUtilities.RunBlender(String script, String blend, Boolean background, Boolean check_version)

at S4Studio.Blender.BlenderUtilities.ImportGeom(String custom_blend, String custom_geom, Int32 body_type, String cut)

at S4Studio.ViewModels.CAS.CASLODItem.ImportMesh(BlenderUtilities blender_util, String blender_path)

at S4Studio.ViewModels.CAS.CASStandalone.<>c__DisplayClass71_0.<ExecuteImportMesh>b__0()

at System.Threading.Tasks.Task.InnerInvoke()

at System.Threading.Tasks.Task.Execute()

--- End of inner exception stack trace ---

---> (Inner Exception #0) S4Studio.Blender.BlenderException:

File "<string>", line 1, in <module>

File "<string>", line 39, in <module>

File "C:\Users\[UserName]\AppData\Roaming\Blender Foundation\Blender\2.70\scripts\addons\s4studio\cas\blender.py", line 122, in save_geom

weight_list[blend_index_map] = min(int(vertex.groups.weight * 255), 255)

ValueError: cannot convert float NaN to integer





at S4Studio.Blender.BlenderUtilities.RunBlender(String script, String blend, Boolean background, Boolean check_version)

at S4Studio.Blender.BlenderUtilities.ImportGeom(String custom_blend, String custom_geom, Int32 body_type, String cut)

at S4Studio.ViewModels.CAS.CASLODItem.ImportMesh(BlenderUtilities blender_util, String blender_path)

at S4Studio.ViewModels.CAS.CASStandalone.<>c__DisplayClass71_0.<ExecuteImportMesh>b__0()

at System.Threading.Tasks.Task.InnerInvoke()

at System.Threading.Tasks.Task.Execute()<---