Hi
For future reference, remember we cannot see the flows or failures, so any answers are based on guesses and experience.
please share the flow run and inputs etc and be clear on what the failure is and where :-) so we can help faster.
The answer is fairly simple though, you have code that you expect to run, but the actual values you are using are blank, which is going to cause an issue.
Its up t you to validate that there are attachments (or in other flows, records, or data at all) before you try to use data that isn't there, or it will fail.
So you need to validate if the attachment is there, using a condition (like abm says). I didnt watch their tutorial but they know what they are talking about.
I just wanted to clarify in words to help you understand. This isn't just about this flow, its a best practice in any flow, for any condition that is going to use data from Get Items or Get Item or List Rows etc etc etc to check that you actually have data prior to attempting to use it.
