Optimization Geometry does not work

[Jeong1647]

I sketched Aspirin Copper molecule, which is a copper complex with two aspirin ligands, into Marvin Sketch. I then converted to sketch into pbd and uploaded into Avogadro. Then, I manually attached the hydrogens manually to the molecule because Avogadro did not include them. I selected all the parts and deselected hydrogens and the the bonds connecting the hydrogens. After that, I went to 'Extension', to 'Fix Selected Atoms'. I then set my force field to Ghemical and began geometry optimization. However, it does not work. I tried UFF as well but no outcome. Any suggestion to fix this issue?