The soviets protested against the Six Power Conference held in London which led to the creation of a new German state by merging the three western zones of occuption.
To the soviets this step violated the Potsdam Agreement and ended the allied adminstration of all zones in Germany. As a direct reaction the Soviet representative Marshal Sokolovsky walked out of the meeting of the Allied Control Council.
Since then the Council never attended to one again and became obsolete. From that point on the building of the Allied Control Council only housed the only remaining Four Power Organization the Berlin Air Safety Center.