Without fail (and I've done this many times) I've noticed the following:
1. First try to open - screen flickers, cursor freezes. Have to use Task Manager to end process.
2. Second try to open - screen flickers, cursor freezes. Have to use Task Manager to end process.
3. Third try to open - screen flickers, cursor freezes. Goes to character selection, Game crashes.
4. Fourth try to open - screen flickers, cursor freezes. Goes to character selection. Game start normally.
EVERY.....SINGLE....TIME
No other changes required, no shortcut addendum switches, no windowing mode, no being silly and altering all your filenames. No rebuilds.
Guess I'll be doing the old 4 attempt shuffle until Anet fire up the QA Hamster.