New ceiling light works does not work
Your new light probably has insufficient terminals and you're connecting wires which should not be connected, causing a dead short.
You need a 4-terminal ceiling rose or connection block: live (red, or brown); neutral (black, or blue); switched live (black with red marker); and earth (bare, sleeved green-yellow).
The earths should all go in the brass terminal to the top left - I can't see where they connect at all, they must not be left unconnected and pushed up into the ceiling - and the lives should be in the middle terminal marked Loop, not in a separate terminal.

http://wiki.diyfaq.org.uk/index.php/House_Wiring_for_Beginners#Lighting