Have you have received the above error message? "Export failed. An unexpected error occurred during the export phase. Please contact your Invitbox Administrator."
This message is fairly generic, but one thing you can try is to resync your Supplier Cards within Invitbox, as you may be trying to export an invoice for a newly created supplier within Invitbox, and seeing the supplier does not yet exist in QBO it would fail to export. To do this go to the Admin tab> Supplier Cards; Edit > click on ‘Sync with QuickBooks Online’ and this will update this new supplier in QBO. After doing this you should be able to export.
Have you received the error; "Duplicate Name Exists Error" ?
This means that there are 2 supplier cards with this name. We can only assume that someone has created one in Invitbox when there was already an existing one in QBO. This can sometimes happen when the new invitbox supplier is being created as they see the green + and click on it, not knowing that the box is a drop down that has QBO supplier cards to choose from.
To amend this you should search for the supplier in 'Maintain Supplier Cards' as shown in image above (to access this go to the Admin tab> Supplier Cards; Edit). If you find 2 of them and one has the source (the 2nd column) shown as 'Invitbox' and one as 'QuickBooks Online' then you need to delete the 'Invitbox' one and then link the remaining QBO supplier card to the supplier via Admin tab> Suppliers; Edit> search for the supplier and click Edit. Then you need to select the supplier card from the drop down list and save.
Then try the Supplier Card sync with QBO again and if that goes well you should be able to export with no problems.
If you did not find that there was a Supplier Card with the same name in QBO, then you should also check for it in the Customer or Employee lists (as the error suggests).
If there is still a problem thend contact Invitbox support (firstname.lastname@example.org) and let us know the error you received.