There could be many reasons a person has a hard time building muscle, especially when starting a new exercise program. First, is nutrition, meaning you need to feed your body with proper calories to provide a healthy environment internally. Your body and your muscles need to be properly nourished, so it is better to eat vegetables and meat (organic if possible), as well as varying the grains one eats from spelt to brown rice to quinoa etc… Try to stay away from anything packaged (bars, cereal, canned fruits-all these foods have some hidden sugars or preservatives.) I believe there should only be three isles at the grocery store: fruits and veggies, meat, and grains. By eating correctly, the body can digest and metabolize better, which will help you lose weight and allow your body to not waste energy on having to digest foods that are full of preservatives and other wasteful calories.
The second thing that can be done to help build muscle is practicing controlled isometric exercises that really focus on the ability of connecting with the muscles and joints. For an example: work on your bicep muscle (a muscle that affects the shoulder and elbow) by flexing your elbow as much as you can and then with your opposite arm place resistance against this flexing motion for 30 seconds. You will notice that this in itself can be very difficult. However, you will gain the ability to connect more to your bicep, as well as all the other elbow flexors. So when you do place a lot more weight or force through that joint, the muscles will be more prepared for that stress. Now, imagine doing this to every joint of your body and reconnecting to movements; rather than using heavier weights or more force and load on joints, which could ultimately cause more stress and pain.

I could go on with other suggestions, but this comment is getting long! Good luck with your weight training!