This morning several of our jobs failed to copy files from Sharepoint Online. These jobs had been working fine for a long period of time. After some investigation it was discovered by our IT team that th origin of the error was the
Apps that don't use modern authentication was set to
Block Access.
Changing this to Allow Access, as suggested in the troubleshooting section of the
documentation resolved the issue.
However, as of
october 2022 , MS willl no longer allow this to work. Our issue was in fact caused by MS changing the setting for random tenants.