okay - opened a ticket and link to here.
Btw. I cannot see any setup remotes anymore under Settings -> Remotes.

When I am adding a new one, it just vanishes upon saving.

@olivierlambert this is not really an option right now. Do you guys have any guesses on what could cause the issue?

syslog while taking a backup:

Oct 8 04:36:41 xoa netdata: EXIT: all done - netdata is now exiting - bye bye...
Oct 8 04:36:41 xoa netdata[83536]: 2020-10-08 04:36:41: netdata INFO : MAIN : EXIT: all done - netdata is now exiting - bye bye...
Oct 8 04:36:41 xoa systemd[1]: netdata.service: Main process exited, code=exited, status=1/FAILURE
Oct 8 04:36:41 xoa systemd[1]: netdata.service: Failed with result 'exit-code'.
Oct 8 04:36:44 xoa xo-server[123232]: 2020-10-08T08:36:44.360Z xo:api WARN crp | backupNg.runJob(...) [83ms] =!> TypeError: Invalid attempt to destructure non-iterable instance.
Oct 8 04:36:44 xoa xo-server[123232]: In order to be iterable, non-array objects must have a Symbol.iterator method.
Oct 8 04:36:46 xoa systemd[1]: netdata.service: Service RestartSec=5s expired, scheduling restart.
Oct 8 04:36:46 xoa systemd[1]: netdata.service: Scheduled restart job, restart counter is at 2276722.
Oct 8 04:36:46 xoa systemd[1]: Stopped netdata real-time system monitoring.
Oct 8 04:36:46 xoa systemd[1]: Started netdata real-time system monitoring.
Oct 8 04:36:46 xoa netdata: Cannot cd to directory '/var/cache/netdata'

syslog
ct 8 04:32:24 xoa systemd[1]: netdata.service: Main process exited, code=exited, status=1/FAILURE
Oct 8 04:32:24 xoa netdata: Cleaning up database [0 hosts(s)]...
Oct 8 04:32:24 xoa systemd[1]: netdata.service: Failed with result 'exit-code'.
Oct 8 04:32:24 xoa netdata: EXIT: all done - netdata is now exiting - bye bye...
Oct 8 04:32:29 xoa systemd[1]: netdata.service: Service RestartSec=5s expired, scheduling restart.
Oct 8 04:32:29 xoa systemd[1]: netdata.service: Scheduled restart job, restart counter is at 2276672.
Oct 8 04:32:29 xoa systemd[1]: Stopped netdata real-time system monitoring.
Oct 8 04:32:29 xoa systemd[1]: Started netdata real-time system monitoring.
Oct 8 04:32:29 xoa netdata: Cannot cd to directory '/var/cache/netdata'
Oct 8 04:32:29 xoa netdata[82958]: 2020-10-08 04:32:29: netdata FATAL : MAIN :Cannot cd to directory '/var/cache/netdata' # : No such file or directory
Oct 8 04:32:29 xoa netdata[82958]: 2020-10-08 04:32:29: netdata INFO : MAIN : EXIT: netdata prepares to exit with code 1...
Oct 8 04:32:29 xoa netdata[82958]: 2020-10-08 04:32:29: netdata INFO : MAIN : EXIT: cleaning up the database...
Oct 8 04:32:29 xoa netdata[82958]: 2020-10-08 04:32:29: netdata INFO : MAIN : Cleaning up database [0 hosts(s)]...
Oct 8 04:32:29 xoa netdata[82958]: 2020-10-08 04:32:29: netdata INFO : MAIN : EXIT: all done - netdata is now exiting - bye bye...
Oct 8 04:32:29 xoa systemd[1]: netdata.service: Main process exited, code=exited, status=1/FAILURE
Oct 8 04:32:29 xoa netdata: EXIT: netdata prepares to exit with code 1...
Oct 8 04:32:29 xoa systemd[1]: netdata.service: Failed with result 'exit-code'.
Oct 8 04:32:29 xoa netdata: EXIT: cleaning up the database...
Oct 8 04:32:29 xoa netdata: Cleaning up database [0 hosts(s)]...
Oct 8 04:32:29 xoa netdata: EXIT: all done - netdata is now exiting - bye bye...

Node version
xo-server config syntax
Disk space for /
Disk space for /var
Native SMB support
Fetching VM UUID
XOA version
Appliance registration
Internet connectivity
npm version
XOA status

{
npm: '4.6.1',
ares: '1.16.0',
brotli: '1.0.7',
cldr: '37.0',
http_parser: '2.9.3',
icu: '67.1',
llhttp: '2.0.4',
modules: '72',
napi: '6',
nghttp2: '1.41.0',
node: '12.18.2',
openssl: '1.1.1g',
tz: '2019c',
unicode: '13.0',
uv: '1.38.0',
v8: '7.8.279.23-node.39',
zlib: '1.2.11'
}

Hi it's a XOA VM, so I do not know the specifics at this moment.
I'll log into the machine and try to get the data.

After upgrade to 5.50.3 I cannot perform any backups.

Backup jobs fail immediately with this error message:

Invalid attempt to destructure non-iterable instance.
In order to be iterable, non-array objects must have a Symbol.iterator method.