I’m in the same situation since the install of Sonarr package on my Synology :
I’ve made some changes. Initially the authorization was set for user sc-download, i put the same to sc-media. Sonarr downloaded to flies, i have a different error message : “The.Expanse.S03E08.It.Reaches.Out.1080p.AMZN.WEBRip.DDP5.1.x264-NTG[rarbg]
No files found are eligible for import in /volume1/downloads/The.Expanse.S03E08.It.Reaches.Out.1080p.AMZN.WEBRip.DDP5.1.x264-NTG[rarbg]”
A question, if the problem came since the last update, can week-end have an official answer ?