Long story
PRC backing up Indonesia communist party to launch Revolutionary movements including several riots over land distribution, in 1965 at least seven high ranking Army generals killed by communist party military arms with China backing. The result is cold blooded killings of Millions Communist party member in Indonesia, closure of China communist embassy in Indonesia, the exclussion of Chinese ethnic in Indonesia from politics scene and other discriminatory policy against China ethnic in Indonesia. In recent years China trying to push their Naval boundary and crossing Natuna sea several Times.
Until now China still bitter against Indonesia