I went back to work more on my project which is building a character for my game.
I made the weight painting already, but I wanted to edit my mesh, and then adjust the weight paint too if it's needed. However after editing the mesh, the weight painting went crazy on all the bones along the limbs: The weights disappeared on the left side, while the right side of the bones has all the weights for both sides. You can see an example of my problem on the image below: While the upArm.R bone has the weight paint for itself and for the upArm.L bone too, the upArm.L bone has no weights.
I would avoid starting over the weight painting process since I polished it a lot from time to time. Can anyone help me?