Critical Error note - Black screen instead of loading screen - Unable to bring up the Task Manager

Just a note for the person who is keeping track of the critical error bug. The version of the bug that I am encountering most frequently is this:

1. You enter champion select.
2. Each player selects and locks their champion.
3. The loading screen doesn't appear - instead you get a black screen with the game cursor present.

You cannot access Task Manager because the black screen is "in front of" all the other windows applications (including Task Manager). This means that you cannot do the dump that the main thread at the top of the forums is requesting. You can see that a critical error message has appeared by toggling via the WIndows key.