Russia's new T-14 Main Battle Tank Broke Down During WW2 Victory Day Parade Rehearsal

link.

That's an impressive practice run for the parade!

However, to be fair, this is a prototype rather than the final production vehicle.  Prototypes have problems.

Update:

More Video.

Bonus Video of the T-15 Heavy Armored Personnel Carrier trying to get on a tank transporter.  Not the fail others are portraying the video unless it canbe determined the problem is the engine is undersized for the weight of the AFV.  Backing a 50ish ton AFV onto a truck is something which is done extra carefully and I would not blame the driver for coming down rather than risking coming off.  OTOH, if the engine really is too little for getting the T-15 onto the transporter, that counts as an epic fail.