Why Fascism invaded Abyssinia in 1935?

Mussolini wanted to create a new 'Roman Empire' (one that would equal the vast empires held by Britain and France at the time) and saw invading Abyssinia as part of this. He was also eager to create a distraction from the economic problems that faced Italy and to avenge the humiliating defeat of the Italian Army in Abyssinia in 1896.

He was encouraged that an invasion was easily possible by the Japanese invasion of Manchuria in 1931. He saw that by taking agressive and decisive action and grabbing what they wanted, the Japanese had easily got the better of the League of Nations and this encouraged Mussolini to attempt the same, by invading Abyssinia.

Than, in 1935 , the reminder of Adua, where Italy was defeated by Ethiopia was very alive.
Mussolini invaded Ethiopia to venge this reminder and also to give Italy an Empire.

it was colonialism of fascist Italy

To build an empire.