Internal storage fills up
It seems your internal app partition is full. Check it on Settings> Storage> under phone storage what left as available on app section. If it is full (150mb free is not usable) you have 2 options: 


You can swap your external SD. You can read full note here: (NB: it works if you have a MTK device, I don't know what if other devices) How to swap phone storage with SD card
Partition of external SD. read it here: How to Partition SD Card and Use Link2SD in any Android Phone with Screenshots


Hope it helps.