I see differents reasons to 400 bad request on your support so i want to be sure what it is :
on the package https://app.skyvia.com/#/packages/70016 i have the message
"An exception has occurred during upsert operation, the message returned from the provider is:
The remote server returned an error: (400) Bad Request."
The file is biger than in the futur because we want to try to import big files to test with skyvia
Is it also possible during tests period with the sandbox to don't have limits on records ?