Hi, I found the solution while trying to write the question so if anyone is facing this issues, or maybe the n8n plugin could try to catch this.
While trying to upload a PDF to a 4.4.9 Seatable I got a 404 error but uploading to a 4.3 instance worked, initially I thought the Upgrade might have been the problem.
Looking at the 404 error however showed this URL: https://foo.example.com//api/v2.1/dtable/app-access-token/
the two // before api in the URL was the problem.
I have entered the url for my seatable server in the credentials with a / at the end, everything else works fine but the upload has a problem with that.
Removing the / at the end of the URL in the credentials fixed the issue.
