Hi Carsten. Thanks very much for coming back so swiftly with such a comprehensive response. I am told that the set-up in this multiplex is that the staff do not even have access to the projector control panels! The screens on the projectors you mention are hidden behind some kind of barrier and everything has to be done through the TMS software. I assume this is because tech for the chain is handled centrally, and they don't want any settings getting twiddled by people who "don't know what they're doing" (similar to corporate laptops where the user can't install software etc without reference to the company IT department). Someone told me they *think* the projectors are 320 series, but not confirmed. But we do know SMPTE validation is a separate process on these projectors so, from what you've said, that does seem likely. It's very frustrating not to be able to get even this basic information. I am trying to get it escalated to the chain's central technical team so we can find out more. I'll come back as soon as have more info. It's good to know this doesn't sound like it's a widespread problem. The DCP which wouldn't play was just a bit of preroll, so it wasn't a disaster. But my worry, of course, is that if this 1 DCP wouldn't play, maybe something else more crucial (like a feature) may also turn out to be problematic later in the festival. In the meantime: I assume when you say SMTPE validation is not just hash-check, you mean it's also XML schema validation, signature validation etc. That fits within the meaning of the term "validation" as I'd previously understood it. Have I read you right? Or are there some esoteric extra checks only Sony projectors do? I am also still wondering: What about Interop DCPs on these projectors? If validation is performed on SMPTE DCPs only, does this mean that these projectors don't do any validation prior to playback on Interop DCPs? That would be quite scary - if corruption was introduced in copying the DCP to server's internal RAID, you wouldn't have any idea that had happened until the projector hiccups in the middle of the public show. I had always thought that these checks were done as part of ingest, so it wasn't something we needed to worry about. But maybe I assumed wrong... Jim On 05/11/2021 22:36, Carsten Kurz wrote: