Trouble sending an invoice from a Canadian address to an American address

[caand_uptf8]

 I am trying to send an invoice to someone in California but every time I try to send it I get the following message: 

There was a technical error - please try again in a moment.

I have read other people having the same issue and clearing it  up by putting the tax rate to 0.  Unfortunately the tax rate is non editable.  If anyone can help or provide a useful suggestion I would be grateful!

[roscobully]

Same problem here, I stopped selling on eBay for a while, now I know why.

[2nd-time-around-jewelry]

This is an ongoing problem for a long time. Even though it says technical  error, I have found that the invoice usually gets sent. Make sure you have a copy sent to yourself & you will see that it has gone through.