Are you using the version of Tvheadend from the App Store? If so, I suggest you try the version recommended by HarryL here: OSMC RC Unable to install TVHEADEND - #13 by EMJB.
Are you using the version of Tvheadend from the App Store? If so, I suggest you try the version recommended by HarryL here: OSMC RC Unable to install TVHEADEND - #13 by EMJB.