Pre-roll won't work

[tom80H]

I believe it’s enough to set it to 0 – with a preroll configured it should still play that.
Can you verify the file is located at that very location and your PMS has permission to see it. As your server is running on a Syno, that’ll be Plex (for DSM 6) or PlexMediaServer (for DSM 7).

Synology FAQ - Questions, Answers, and How-To's

FAQ 19: Setting permissions to allow Plex access to media files Before beginning, it’s important to remember one key point; Plex doesn’t have any special privileges on Synology except for being able to access the Video Transcoding acceleration hardware. It cannot read any of your files unless you expressly grant permission. This is a fundamental principle of Linux (which Synology uses for DSM) Because of how Synology grants permission, access to files is broken into two different …