Your entire timeline has red lines. If all the clips are stills, then that's fine, but if there are video clips then it suggests your project settings are wrong.
Unless you have some items on a higher track you should either close that gap, or fill it with something (e.g. black space or an empty title. Technically PRE should be OK with blank space but for some it doesn't.
Insanity is hereditary, you get it from your children