yep Mono found some new updates was on 6.8.0.105 previously… Sonarr on latest version from March.
i dont know whats happened but at somepoint Sonarr as forgotten the link to my external hard disk 
it now just shows.
Location Free Space Total Space
/ (PARTUUID=6f0c83bc-02) 11.6 GB 29.2 GB
and should also have listed
/mnt/281EC3A11EC36682/TV Shows/ with free and Total space
So now when it indexes it says Zero Meta data …
the above mnt does exist and is fine from Plex. just no longer linked in Sonarr.
What happens if you re-add it? Could it be a permission issue?
Ok so I just got a crash from radarr - so clearly the issue still exists. Sorry for any false hope
dietpi@DietPi:~$ sudo systemctl status radarr
● radarr.service - Radarr Daemon (DietPi)
Loaded: loaded (/etc/systemd/system/radarr.service; disabled; vendor preset: enabled)
Active: failed (Result: signal) since Tue 2020-05-19 20:17:46 AEST; 1 day 13h ago
Process: 11238 ExecStart=/usr/bin/mono --debug -O=-aot /opt/Radarr/Radarr.exe -nobrowser -data=/mnt/dietpi_userdata/ra
darr (code=killed, signal=ABRT)
Main PID: 11238 (code=killed, signal=ABRT)
May 19 20:17:46 DietPi mono[11238]: at System.Data.SQLite.UnsafeNativeMethods:sqlite3_close_v2 <0x00037>
May 19 20:17:46 DietPi mono[11238]: at System.Data.SQLite.SQLiteBase:CloseConnectionV2 <0x000d3>
May 19 20:17:46 DietPi mono[11238]: at System.Data.SQLite.SQLiteConnectionHandle:ReleaseHandle <0x000ab>
May 19 20:17:46 DietPi mono[11238]: at System.Runtime.InteropServices.CriticalHandle:Cleanup <0x00077>
May 19 20:17:46 DietPi mono[11238]: at System.Runtime.InteropServices.CriticalHandle:Dispose <0x00017>
May 19 20:17:46 DietPi mono[11238]: at System.Runtime.InteropServices.CriticalHandle:Finalize <0x0002f>
May 19 20:17:46 DietPi mono[11238]: at System.Object:runtime_invoke_virtual_void__this__ <0x0008b>
May 19 20:17:46 DietPi mono[11238]: ================================================================
May 19 20:17:46 DietPi systemd[1]: radarr.service: Main process exited, code=killed, status=6/AB
RT
May 19 20:17:46 DietPi systemd[1]: radarr.service: Failed with result ‘signal’.
Nothing in radarr.txt log. I’m not sure how to read logs.db
I think for me, i might move to a docker based Sonarr/Radarr anyway
Got the sonarr docker running, very easy to setup and utilise your current config.
If you need help lmk.
Migrated sabnzbd and radarr to Dockers too. Working good so far.
How does this resolve the crash issue? I was just about to try downgrading mono but wouldn’t be averse to trying a sonarr container.
So you have any tutorial or something like that on a link?
I’ve run apt update && apt upgrade on the pi and now it seems stable. Perhaps the last version of dietpi missed something?
no joy for me still… but the auto restart service means it just crashes and restarts on its own.
What link did you use to get Docker working? and can a Container see a local mounted USB Drive?
Ok so this will assume you already have sonarr up and running and configured. I only use sabnzbd with sonarr so i can’t help you much if you use it with a torrent client but you should be able to figure it out.
To answer the previous poster YES it will see your USB drives within the docker.
I’ll try and mark all the commands in code text so it’s easy to see what you need to type and what is my ramblings.
First lets stop sonarr from running and disable it from starting back up
sudo systemctl stop sonarr
sudo systemctl disable sonarr
Make sure you have docker installed by using
sudo dietpi-software
Make sure you’re logged in as the user dietpi and create a folder for the config of sonarr from within the home directory of the user diet
mkdir /home/dietpi/sonarr
Login as root
su
The following command will install the docker. The formatting is important, but if you screw it up it won’t matter you can always restart this process.
For TZ copy and paste your own timezone from here and overwrite the antarctica one in my example:
https://en.wikipedia.org/wiki/List_of_tz_database_time_zones
Assuming you use port 8989 leave that section as is. However let’s say you currently use 9898 make it say -p 9898:8989 (that maps the internal port of the docker that sonarr is using 8989 and makes it available externally on 9898).
The -v is going to give the docker access to your servers file system and map it to a filesystem on the inside of the docker. For simplicity and compatibility with the NZB/Torrent app, I strongly suggest you map it to the same mount point on the server as inside the docker. The location before the colon is the servers location, after the colon is what it is mapped to on the docker
For example if I had an external hd mounted as /mnt/external I would map it inside the docker as /mnt/external.
-v /mnt/external:/mnt/external
Sonarr needs access to the place where your NZB/Torrent app downloads to and also the location where you want it to finish up in. Eg if your nzb app downloads to:
/mnt/external/downloads
but the final renamed file ends up in
/mnt/external/tv
Then just mount /mnt/external (it will cover both) with:
-v /mnt/external:/mnt/external
However if your downloads are saved in:
/home/dietpi/downloads
and your finished location is
/mnt/external/tv
you will need to mount both locations in the docker, so use two lines
-v /home/dietpi/downloads:/home/dietpi/downloads
-v /mnt/external/tv:/mnt/external/tv
We will also map our folder we created before as /config. We will copy our config we already use in sonarr into it later
-v /home/dietpi/sonarr:/config \
Ok so now we should be good to create the docker!! Fill in the details below based on what you need and copy/paste this (yes the whole thing) at the command line and press enter. Don’t mess the formatting up - make sure you run as root.
docker create \
--name=sonarr \
-e PUID=1000 \
-e PGID=1000 \
-e TZ=Antarctica/Syowa \
-e UMASK_SET=022 `#optional` \
-p 8989:8989 \
-v /home/dietpi/sonarr:/config \
-v /mnt/external:/mnt/external \
--restart unless-stopped \
linuxserver/sonarr
It will go ahead and download the docker image based on your hardware. Assuming you have compatible hardware, eg x86 cpu, raspberry pi etc it will all work nicely.
Let’s start the docker and check things are working without our config:
docker start sonarr
with your internet browser connect to:
http://youripaddresshere:8989
Make sure it loads - that’s all we care about for now
docker stop sonarr
Now we want to copy our config from sonarr that we have in dietpi already.
Do this as your dietpi user:
cp -r /mnt/dietpi_userdata/sonarr/* /home/dietpi/sonarr
Now we should be good to go!
docker start sonarr
with your internet browser connect to:
http://youripaddresshere:8989
With any luck you should be done. Check the sonarr logs for any warnings/errors.
If you have radarr, it’s almost the same to do it:
sudo systemctl stop radarr
sudo systemctl disable radarr
as dietpi user:
mkdir /home/dietpi/radarr
cp -r /mnt/dietpi_userdata/radarr/* /home/dietpi/radarr
as root user:
docker create \
--name=radarr \
-e PUID=1000 \
-e PGID=1000 \
-e TZ=Antarctica/Syowa \
-e UMASK_SET=022 `#optional` \
-p 7878:7878 \
-v /home/dietpi/radarr:/config \
-v /mnt/external:/mnt/external \
linuxserver/radarr
docker start radarr
with your internet browser connect to:
http://youripaddresshere:7878
Bonus - how to install sabnzbd as a docker (no cfg copy though you can probably do that if you can find it)
as dietpi user:
sudo systemctl stop sabnzbd
sudo systemctl disable sabnbd
mkdir /home/dietpi/sabnzbd
as root:
docker create \
--name=sabnzbd \
-e PUID=1000 \
-e PGID=1000 \
-e TZ=Antarctica/Syowa \
-p 8080:8080 \
-p 9090:9090 \
-v /home/dietpi/sabnzbd:/config \
-v /mnt/external:/mnt/external \
--restart unless-stopped \
linuxserver/sabnzbd
docker start sabnzbd
with your internet browser connect to:
http://youripaddresshere:8080
======================================================
If you stuff up and want to go back to what you had
As root:
docker stop sonarr
docker rm sonarr
systemctl enable sonarr
systemctl start sonarr
======================================================
After you are happy everything is running ok make sure to uninstall sonarr from dietpi-software
I hope this helps, it looks tricky and it might be if its your first docker. If this works for you take a look at the other great dockers provided by linuxserver.io they all follow a similar idea to what you learnt with this:
https://hub.docker.com/u/linuxserver
GaryD that a brilliant write up… i might give it a go .
Let us know how you get on in the next few days if it still stable… or if Sonarr/Mono have complete broken something in there recent builds.
Btw is someone still in touch with sonarr guys to check why its continue failing?
i posted on forum.sonarr.tv and had zero support there… maybe the wrong place?
Yeah I’ve posted quite a bit on their support discord. All the devs are there regularly. Current recommendation is to try rolling back the mono install to 5.20.x to see if that fixes the issue.
do they explain how to rollback to the other mono version?
“Their site has details, you just set a snapshot in your sources.d and bob’s your uncle.”
https://www.mono-project.com/docs/getting-started/install/linux/#accessing-older-releases
ok did they point out which snapshot to use?
No. 
I haven’t found the list of snapshots yet.
So, like
su - dietpi mkdir /home/dietpi/sonarr
?