In Deathly Hallows, before the Ministry fell, it is mentioned numerous times that nobody could Apparate to the Burrow due to all of the protections places on the yard. Wedding guests had to Apparate right outside the gate of the yard. So when the ministry fell, how were the death eaters able to Apparate right into the tent?
1 Answer
The Death Eaters broke the protections
“The Death Eaters got through all those protective charms?” Harry asked, remembering how effective those had been on the night he had crashed in Tonks’s parents’ garden.
“What you’ve got to realize, Harry, is that the Death Eaters have got the full might of the Ministry on their side now,” said Lupin. “They’ve got the power to perform brutal spells without fear of identification or arrest. They managed to penetrate every defensive spell we’d cast against them, and once inside, they were completely open about why they’d come.”
—Harry Potter and the Deathly Hallows
Having taken over the Ministry, the Death Eaters were able to mount a far more coordinated and powerful attack on the protections on the Burrow than they could have done previously. They had the support of Ministry Aurors, magic, and knowledge, and they could use spells that would otherwise have tripped the Ministry's sensors.