Transfering into void mode while during a boss cutscene causes you to lose control of your character.

[Aurora3500]

If you use transference during a boss cutscene, it will cause you to completely lose control of your character and be unable to bring up the escape menu.

My character kept walking in place and I could not do anything, I had to wait for my operator to die, and then when an enemy finally killed my Warframe, I couldn't control my Warframe either and was unable to revive.

Even after reviving, still couldn't do anything and ultimately the only way to fix it was to use task manager to end the game. It couldn't be done normally.