Encountered a communication error (https://arl2.api.myob.com/accountright/2fb9312c-59b7-46ff-8f40-59da18d7166e/Sale/Invoice/TimeBilling/?returnBody=true)

Inner Exception : The remote server returned error  500 internal server error.

Errors : ''

Message  : Encountered a communication error (https://arl2.api.myob.com/accountright/2fb9312c-59b7-46ff-8f40-59da18d7166e/Sale/Invoice/TimeBilling/?returnBody=true)

source : "MYOB.AccountRight.SDK".

I am able to sync other items like customer, employee and jobs but in case invioices I get this error from api?