Program blocked when I use 3D adding new track

Hi, I’m delighted with this program, having used others previously. But I have a question, why the program block when I enter titles in new track, in 3d? … the program does not play, overlap or not show the overlay if it plays … it seems that the computer does not have resources when at most, is used 33 percent of total CPU power. I need help with this. Thank you!!!