Invoice app cutting out

Hi there,

I've managed to use the MYOB invoicing app a few times over the last month or so but now find that when I enter an invoice it cuts out immediately after I add an item and returns to my phones home screen. A window briefly appears saying something went wrong but disappears as quickly as it appears. 
I have uninstalled and reinstalled the app but that doesn't seem to fix it. 
Has anyone else come across this? Does anyone have a fix?

Thanks in advance 

Brett