Earlier this year, Eventbrite changed some of their code on their website without telling anyone in advance. As it turns out, their new code is not compatible with the Windows Server (v2012R2) that the Blackbaud Boston datacentre runs on, which most US Clients are also on. It does work on Windows Server 2019, which is the operating system of the Blackbaud Azure datacentre. As a result, Blackbaud plan on updating their Boston datacentre to Windows Server 2019 by the end of the August 2023.
They hope to give us an exact resolution date closer to the time, but as of yet, we haven't had an update.
In the meantime, you should still be able to extract that data out of your Eventbrite directly, export it onto a spreadsheet and use the File (csv or Excel) data source option in Importacular to complete your import