Hi.As i've posted before, I tried to export FBX of the character and then make editing on the mesh.There were 4 fingers but 5 finger rig in the original FBX.I tried to copy the mesh of a fingr and then add to empty rig there was in the original rig.However, when i tried to upload to 3dxchange that edited FBX , the rig looks like it doesn'T attach to mesh, and all the face looks messed up.
https://forum.reallusion.com/360971/Urgent-Help-Needed-Editting-FBX-in-Maya-Causing-Unknown-Problems 
This was the post i've posted, that's why i didn't give details.

However , more than this problem, i wanna know that what are the things i should do when edit the import in  3d software like Maya ? It's not about maya. 
I just want to know what are things i must avoid and what are things i must do if i edit a model that exported from 3dxchange ?

@ edencorvo
Hi ....
I'm not a Maya user atm anyway, but maybe you could clarify the types of 'errors' you're getting.
Are you talking TEXT error alerts, or errors in the re-imported mesh (mangled or whatever).
Would be ideal if you could post a 'screen shot' - then someone on here's bound to be able to help.
Cheers....

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Please be patient with me ..... I don't always 'get it' the first time 'round - not even the 2nd time! :(  - yikes! ... 

● MSI GT72VR Laptop, i7 7700HQ 4-Core 3.8 GHz 16GB RAM; Nvidia 1070, 8GB Vram ● iClone-7.93 ● 3DXChange Pipeline 7.81 ● CC-3 Pipeline 3.44 ● Live Face ● HeadShot ● Brekel Pro-Body ● Popcorn FX ● iRAY ● Kinect V2 ● DaVinci Resolve17 ● Mixcraft 8.1

Okay title is weird. 
I do the
"Export FBX from 3dxchange ---> Import to Maya ----> Edit The Mesh Without Changing Rig System ----> Import FBX to 3dxchange "
circle for days.

All i'm getting is tons of errors. 
Is there a checklist or things to avoid when triying to edit a character in Maya (or any kind of 3d modelling software) ????

PLEASE HELP ME. :(