Shipping slip not recognized by VintedGo

An unprecedented problem.

Via the messaging system, it’s impossible to get the shipping slip: clicking on « Print shipping slip » leads to nothing. Never mind, I also received the document by email, voilà, printed on the package.
But the VintedGo locker refuses the package. An error message says « anomaly ». I call the hotline: they tell me that « Vinted canceled the slip ».

No way to contact support for this sale at this stage. The different links offered by the site never lead to the contact interface, perhaps because the transaction only dates from the day before yesterday. In the meantime, many other VintedGo slips have been generated without any problem

Lots of issues with slips, scanning etc. at the end of this week… Other than cancelling the sale and offering it again to the buyer, I don’t see anything else to do if support is unreachable