Ive ran into this issue in the past and to solve it i have to delete and restart my project. I dont feel like deleting about 2 hours of work this time.
I cant select all the items for editing no matter what mode im in. When im in either Object or Edit mode and i hit “A” everything except one object turns red. Heres a couple screen shots of what i mean. How do i fix this? I would like to add a material to this.