Unspecified file format, please help

ive search through the internet about this, and so far i have no luck

i have a skp file that is around 90mb (Nexusphere.skp - Google Drive)

its a big project for my thesis, and trying to open skb/skp wont help, as soon as i close that file, i cant open it

i cant redo all of that due to time and complexities

i dont know why, but this never happened to me before, this is the first encounter to this error

can anyone help me?

i use sketchup pro 2019 to do most of the model