CRM App - Leads - Grid will not loads - Get Error message error code 0x0 (iOS and Android)

I have set the standard CRM App to communicate to ur CRM online instance, all is working OK apart from leads, when I select leads it seems not to be able to load the Grid view and then after a short time I get the following error message:-

Error

Sorry, something went wrong. please try again, or restart the app. error code:0x0

If I select the ...  button in the bottom right hand corner the App is not displaying nay option there seems to be  a loading issue... Any ideas

Thanks

Stu