Electrical Questions? Ask an Electrician Online.
Hi, I'm Mike G and I'll be assisting you. Are you turning the breaker fully to the off position before trying to turn it on?
Examine the wires where they enter the box. Sometimes when installed, when the sheath is removed a wire may have its insulation cut. When you moved them while dropping the fixture they may have shorted.
The question remains open, come back as you have been doing when you're ready to continue.