Currently board backups are limited to 1 GB but there’s no way to know if a board is too large to back up until you try and nothing happens. Therefore, the only solution is to go back and move or delete existing content (inefficient).
The size of the board should show up in “board details” so teams can monitor the size of their boards and create new ones when they are reaching the size limit. At the very least, something should pop up telling you the board was too large to download a backup so you aren’t left scratching your head. This size limit is also not mentioned within the backup options - I only learned about it through customer support.
