My programmer disappeared and I need to find other: what Do I need to install to open my project?

Hello my friendS!
I am not a programmer,just an artist, and developing a game with Unreal. My game is almost finished, but, now I need to find a nre programmer, because the previously disappeared.
FIrst, before looking for a new programmer, I want to open the project and make some tests, and make a list with things fix.

Howevver I can´t open the prohect, ths following message appears:

SO, my qquestion is, does anyone knows what I do need to install to make the project works?

Thanks for attention!