I was just done making clothe mesh for my character and tried exporting it as OBJ or FBX,
then i uploaded my OBJ on mixamo to rig it as usual and then i saw that some of my mesh clothes were not there, I tried selecting them as im exporting but nothing worked so far,
I tried export all and selected only, none of them is working, i should mention that i got the shoes from another model so i just cut the mesh and added it to my current character and then this happend.