How do I find out a compile error that wont show up.

Hey guys. So I just downloaded unity today and I just decided for learning purposes I was going to do the Roll a ball project. I got to the part where you animate the pick up object to turn and then I decided to test it out. After that, I hit play, and noticed there was an error. (I also don't remember what the error is) So, I fixed it, and I hit play and it wouldn't let me do it! I looked at the bottom right corner, and nothing was there! I tried over, and over again, and then I went back to check every detail a few times. Any ideas in how you guys could help me?