Nice to be introduced to a new community 
I hope someone can help me sort out what appears to be a permissions conflict or similar on my Transmission installation. I’m using a Synology DS1813+ that I have recently upgraded to DSM7.
Below is the long and tedious version which I hope helps but happy to provide further details to resolve. I have made bold the most relevant sections in case TLDR:
I attempted to install Transmission 3.00-19 from SynoCommunity in package center which did not work (received error about incompatible version which seemed odd but presumably a conflict having not uninstalled the prior DSM6 package centre version). I uninstalled the old version of Transmission and lost the config, deciding that I could add my previously seeding torrents manually and verify local data once I had Transmission up and running again.
Subsequently installed Docker and now have a functional transmission container, but with issues.
I can successfully download and seed torrents, but am restricted to everything being downloaded to the /downloads/incomplete folder only. Regardless of the folder I instruct transmission to download to, torrents always land in “incomplete” and stay there. The previous version of Transmission didn’t do this, it would download the torrent files directly to the target folder as I entered it.
I can see in the log file that Transmission is attempting to move files on completion, but is getting “permission denied” error as per example below.
[2021-09-25 02:35:22.857] NEPTUNIAN MAXIMALISM - Éons error moving “/downloads/incomplete/NEPTUNIAN MAXIMALISM - Éons/cover.jpg” to “/volume8/Torrents New/NEPTUNIAN MAXIMALISM - Éons/cover.jpg”: Unable to create directory for new file: Permission denied (/home/buildozer/aports/community/transmission/src/transmission-3.00/libtransmission/torrent.c:3299)
I have set Read/Write permission for appropriate volumes and user “sc-transmission” as explained here Permission Management · SynoCommunity/spksrc Wiki · GitHub but that has made no difference.
Also tried creating a new destination shared folder in case there were permission issues resulting from the previous DSM6 version, which also didn’t work.
Not sure how to resolve, your help appreciated