What were Hermann Göring’s soldiers doing in the barracks?

The Engineer Corps left the barracks

During the mobilisation, on the brink of the Second World War in 1939, the Engineer Corps left the barracks. Therefore, the barracks had room for an infantry regiment and several smaller units.

During the occupation, the Germans used the barracks...

To train the soldiers of Hermann Göring's Ersatz- und Ausbildungsdivision.

And when the Netherlands was free again?

When the Germans capitulated on May 5, 1945, and the Netherlands was free again, the barracks were practically unusable. The barracks had been ransacked, many windows were smashed, and any furniture had been looted.