App issues?

Hi all, it seems I have app issues with MYOB and I’m trying to sort it out. 

Firstly, my customers never load, if I’m using a reoccurring customer, I can’t use the app, it tells me “somethings gone wrong” and to try again, which never works. 

secondly, if it’s a new customer, I can fill out the details, that works fine, but when it comes to typing the invoice if I use service, same thing happens, “somethings gone wrong” if I use item, I can’t add lines to my invoice or it just sits there and loads nothing. 

what am I doing wrong ? 

I can literally only view invoices on the app..