Hey Thanks for the response.
About that extra "head"
it’s because Tortuga gives you the option to remove Categories it auto searches from.
It defaults to the "other>Misc> category but you can’t move it. All you can do it add more. I left it as is.
That’s not new on that site and it worked before.
Thanks again for looking.
Hopefully you’ll see what I’m clearly missing.
I just wanted to add to this, that I’ve been having exact same error in sonarr last few days. Using NZBGeek as indexer. I don’t really have any additional info to add though beyond other inputs already provided. I did attempt switching to develop branch of Sonarr and still have the same issue on 2.0.0.5200
Its happening on every single nzb it attempts for the last few days. None have worked successfully.
OP here, thanks all for jumping in to raise the issue.
Just as an extra data point, I don’t believe the nzb I used had an extra section.
The code that is doing xml validation appears to have been introduced in version v2.0.0.5085 going forward, so every version after this is affected. Does anybody know a way to safely downgrade, for instance to the release before it v2.0.0.5054, so we can unblock while it can be investigated and/or fixed forward?
Just opened an issue as well: https://github.com/Sonarr/Sonarr/issues/2554
Please provide the info others have about their setup, are you also running mono 3.10?
Only 3 reports, on one reported version of mono (3.10) leads me to believe it’s a mono issue and isn’t affecting everyone.
Thanks for the advice on upgrading mono @markus101, that totally worked!
I was able to at least upgrade mono to 4.6.2 via the pkg install mono command and restarted sonarr 2.0.0.5163. (installing the mono package overwrote the links to the older version mono in /usr/local/bin and sonarr restarted cleanly without a hitch)
Hey thank you all so much! I got it working now too. Mono was definitely the issue.
As I said above I use Freenas so i opened the shell for the sonarr jail and ran the “pkg install mono” command.
Updated the mono on my Sonarr from 3.10.0 to 5.2.0 and that did it.
Thanks again everyone.
@markus101 Mono was definitely the problem. Thank you for your suggestion.
Here is my information:
Sonarr Version - 2.0.0.5163 (That’s when problems started, previously was on Version 2.0.0.5153)
Mono Version - 4.2.3 (previously 3.1.0)
on Docker (Unraid OS)
did docker -it Sonarr bash to get access to the container. then followed the instructions on Mono Download page for Ubuntu 16.04. Mono was upgraded from 3.1.0 to 4.2.3, problem solved.
Note: I’m a noob, if there is an easier way how to update Mono, please don’t laugh at me 
Hi there, I am having exactly the same issue, but I do not understand this ‘Mono’ fix!
Can someone please explain how I update/install this fix?
I am running Sonarr on MacOS High Seirra version 10.13.4
Many thanks in advance!
Managed to download pkg for MacOS, installed and restarted Sonarr. Mono updated and now working fine.
Thanks for this thread!
I am also running MacOS HS and have the same issue.
a quick read of the installation gubbins, I can see that Mono is a Linux thing.
Wonder what has caused the MacOS one to fail?
Did you fix it ok?
This is the file I downloaded and installed:
hi there
many thanks, this worked a treat and Sonarr is back to normal
thanks 
I’m running on Raspbian 8 and I’m getting the same error now. It was working fine up until yesterday. I don’t know a whole lot about Linux so I’m not sure what changed. I’ve tried apt-get updating Mono but it says it’s at the latest (3.10.0). I haven’t been able to find anything about how to update to a later version. I’ve done the steps at http://www.mono-project.com/download/stable/#download-lin-raspbian and it still says it’s on version 3.10.0.
Any suggestions?
Thanks.
Having similar issues. Everything was fine, now as of this Friday nothing will download due to similar error in this post.
"[v2.0.0.5163] System.Xml.XmlException: Syntax Error after ‘<!’ characters. http://www.newzbin.com/DTD/nzb/nzb-1.1.dtd Line 1, position 3."
I’m running Sonarr inside a docker on top of unraid. Doesn’t appear anything has updated or changed recently, not sure why this is occurring all of a sudden. Will continue to watch here for updates…
FIXED: Removed older NEEDO image or sonarr and installed new linuxserver image. All good now. thanks!
I was able to run pkg install mono in my jail and have it complete successfully. When I run pkg info mono I get told that I am running version 5.2.0.215_1.
However, the Sonarr system page still says I have version 3.10.0. What am I missing here? Running pkg install mono again just tells me that I am already on the latest version.
This is on FreeNAS 9 btw.
EDIT: And yes, I have tried restarting the Sonarr service as well as the jail it is contained in. No luck 
I just tried the command `mono -V’ and it says that it’s still 3.10. What am I doing wrong?
Hello All I think this issue is coming up again.
I got the same syntax error a week or so ago so I ran the the " pkg install mono" in the sonar jail and all worked well again (back to 5.2.0)
Today I check and the mono is back to 3.1.0 and running the command says it’s already at the latest level.
Anyone have any new ideas? Did i forget to delete something?
I’m having the exact same issue.
in the jail it says I’m on 5.2.0 but Sonar says I’m on 3.1.0 and gives me those syntax errors again.
restarted Sonarr, Ran the update command, No luck.
I’m on Freenas 11.1-U4
I ran into this error on freenas 11 using the Sonarr plugin version 2.0.0.3732 PBI sonarr-2.0.0.3732-amd64.
pkg install mono was upgrading the system mono, but sonarr wasn’t updating because it was using its own mono binary:
# cat /usr/local/etc/rc.d/sonarr | grep mono
procname="/usr/pbi/sonarr-amd64/bin/mono"
I switched that procname in the start up script /usr/local/etc/rc.d/sonarr:
# cat /usr/local/etc/rc.d/sonarr
#!/bin/sh
#
# Author: Mark Felder <feld@FreeBSD.org>
#
# $FreeBSD$
#
# PROVIDE: sonarr
# REQUIRE: LOGIN
# KEYWORD: shutdown
# Add the following lines to /etc/rc.conf to enable sonarr:
# sonarr_enable="YES"
. /etc/rc.subr
name="sonarr"
rcvar=sonarr_enable
load_rc_config $name
: ${sonarr_enable="NO"}
: ${sonarr_user:="sonarr"}
: ${sonarr_data_dir:="/usr/pbi/sonarr-amd64/sonarr"}
pidfile="${sonarr_data_dir}/nzbdrone.pid"
procname="/usr/local/bin/mono"
command="/usr/sbin/daemon"
command_args="-f ${procname} /usr/pbi/sonarr-amd64/share/sonarr/NzbDrone.exe --nobrowser --data=${sonarr_data_dir}"
start_precmd=sonarr_precmd
sonarr_precmd()
{
export XDG_CONFIG_HOME=${sonarr_data_dir}
if [ ! -d ${sonarr_data_dir} ]; then
install -d -o ${sonarr_user} ${sonarr_data_dir}
fi
}
run_rc_command "$1"
I was then getting a SIGSEGV related to my sqlite install. I removed my system version of sqlite3 (sqlite3-3.23.1) and downgraded to sqlite3-3.13.0 and then restarting sonarr got everything back up and running correctly again:
root@sonarr_1:~ # pkg delete -f sqlite3
Checking integrity... done (0 conflicting)
Deinstallation has been requested for the following 1 packages (of 0 packages in the universe):
Installed packages to be REMOVED:
sqlite3-3.23.1
Number of packages to be removed: 1
The operation will free 5 MiB.
Proceed with deinstalling packages? [y/N]: y
[sonarr_1] [1/1] Deinstalling sqlite3-3.23.1...
[sonarr_1] [1/1] Deleting files for sqlite3-3.23.1: 100%
root@sonarr_1:~ # fetch "http://pkg.freebsd.org/freebsd:11:x86:64/release_0/All/sqlite3-3.13.0.txz"
sqlite3-3.13.0.txz 100% of 677 kB 1071 kBps 00m00s
root@sonarr_1:~ #
root@sonarr_1:~ #
root@sonarr_1:~ # pkg add sqlite3-3.13.0.txz
[sonarr_1] Installing sqlite3-3.13.0...
[sonarr_1] Extracting sqlite3-3.13.0: 100%
Hopefully this helps
Thanks this worked for me (editing the rc.d init file) although I didn’t need to downgrade sqlite3
Hi,
Am having same error since Saturday, 9th.
Have sonarr as package installed on OpenMediaView and can’t upgrade Mono easily as a newbie.
Anything else I can try please?