Spyder IDE is a complex but usually stable Python program. When something goes wrong with Spyder, often the symptom is it simply won't appear, maybe you'll just get the splash logo. To totally reset Spyder (erasing all user preferences for Spyder), type in Terminal / Command Prompt:
Normally, that fixes Spyder.
To diagnose further, start Spyder from Terminal instead of OS Start menu, it might give some hints.