If the Player closes right after being started and you get the message of a "critical rendering error" it could be for the following reasons:

  1. The graphic sybsystem has become unstable
    This can happen for many reasons: connecting/disconnecting monitors, a problem in old graphics drivers.
    Pleas try to restart the PC from a clean reboot and try again.

  2. A "Window" (grabbed) resource has been added, but the graphics card is not compatible.
    It can happen especially for PCs (laptops) with hybrid graphics cards, see this solution to understand better.

If you are unable to solve the problem, in order not to loose the current project follow these actions:
  1. Start the player with a mouse right click on the Play button, a popup menu will be shown
  2. Choose "Start with disabled Resources".

The player will start without loading resources and in a blank set.
Do not play any set, instead go to the Resources panel and delete all Window resources that may cause the problem.
Then, start the Player again in normal mode.