Actually, it's quite simple.

Just do an "if/else" method set to 'character'. Then do "if 'character' is within 1 meter of 'object' move backward 1 meter" Else, do nothing.(click the character in the object branch and click "new method" then put the latter series of code)You only have to do this once and all objects should be solid.

I have a Mac and collision detection never works. So somebody try tell me if it works. It should work on PC. It does in my Mirror's Edge game.