I've only owned a Mini 2 for a few weeks, and been on this forum for about the same time but even in that short period of time I've read several post about "changing propellers and the drone won't take off".
It's very easy, make sure you put the correct propellers on the correct motors.
Look at the propellers, some have a little raised line near the hub, some don't.
Look at the drone arms, some have a little line near the motor, some don't.
Make sure you put the propellers with the lines on the motor at the end of the arm with a line.
Sorry if it's a bit basic but thought it might help someone.
It's very easy, make sure you put the correct propellers on the correct motors.
Look at the propellers, some have a little raised line near the hub, some don't.
Look at the drone arms, some have a little line near the motor, some don't.
Make sure you put the propellers with the lines on the motor at the end of the arm with a line.
Sorry if it's a bit basic but thought it might help someone.
I've spent the last five years on the Phantom forums, owning a Phantom 3 Advanced. Now I've upgraded to a 
