L_Clavice and R_Clavice don't work here. Maybe the Arm bone... By the way, how do you port a model into GV?
Yep, for this model, it's L_Shoulder and R_Shoulder

GV, as I understand it, is an abbreviation for Granny Viewer ;)
Well, it's very simple... you don't need to port anything, just extract the necessary file. In this case, it will be the file 58840892-29E6-432C-928B-8F629C628147 from data\data.pak\bin\Skeletons\
Copy it to the appropriate directory and change its extension to .gr2
Then, just double-click it, and Granny Viewer will open it automatically - The old lady takes care of you and your health! ;)
But it will open without any markings in the tree, but we know for sure that there are no fortresses that the Bolsheviks wouldn't take! Therefore, we will enable the necessary nodes in the node panel in the menu (left side, above the Granny Viewer logo): Joints, Bone Connectors, and Bone Names
By the way, sometimes it happens that the bone names overlap, and it becomes extremely difficult to read, but it is possible thanks to another utility from the respected comrade CrazyPill - gr2_mel. The result is a file for Alias Maya, in plain text, i.e., you can open it with Notepad or something more advanced and see the names of all the bones! Usually, common and repetitive bone names are used in all models, but often you come across unique and twisted ones, i.e., if a common name looks like L_Shoulder, then a twisted one can easily look like Main|Joint1|L_Shoulder|joint_2
Again, all this comes with practice!

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Неудачное планирование ведёт к неудаче ...
NCF - мод, добавляющий дополнительных существ в HeroesV 3.1