I heard back from support
“I heard back from Engineering. Your script is failing because we plugged a security issue that surfaced. As a result of that fix, we no longer allow redirects.”
I am not an expert, so I don’t know how much of a security risk this is - but it leaves me rather stuck. I’ve spent ages developing Google Apps Scripts - got them working perfectly - and now I can’t use them at all.
Anyone know any other options?