User Activity

Starting last night i am having a problem sending out invoices to new purchases.i am getting 2 types of errors when i try: The first is the red banner with:Something went wrong. Please try again later. The second says:You have not specified shipping ...
I get endless daily messages from customers asking me to send them an invoice for the items they have in their cart, and i always reply that i cant see their cart or their purchases till after they commit.I also ask them to use the REQUEST TOTAL butt...
If you are wondering its been days and ebay still cant fix that....  
This has been happening for a month now.customer put items in their carts, then on checkout they are processed twice or thrice. meaning the customer ends up with 2 or 3 multiples that they didnt ask for. and then i need to cancel the excess maually.e...