There are several problems that you may encounter. Here are some issues that you may face and how you can solve them: 1. Too much light can lead to overheating. A typical tell-tale sign is light or scorched leaves. Solution: If your plant can't handle the heat and light of mid-day sun, you should move it temporarily to a shaded area. Misting also helps a lot.  2. Overfertilizing may also cause issues and discoloration for your indoor bonsai. You may see this manifest if the leaves closest to the roots look yellow and wilted. Solution: Switch to a milder, preferably urea-free fertilizer.  3. Like other plants, pests may also infest your bonsai. Some typical pests include aphids, mealybugs, and weevils, among others. Solution: To prevent the infestation from spreading from one plant to another, make sure to isolate the affected bonsai. You can also use organic pesticides to get rid of the pests.