Tvheadend

after upgrade cannot start tvheadend service.
Ubuntu 16.04
sudo service tvheadend start fails and service does not start after config fatal error.
was able to start by sudo tvheadend f -u hts -g video --nobackup
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May 15 13:57:39 flanders systemd¹: Starting tvheadend.service...
May 15 13:57:39 flanders tvheadend⁸⁷⁷: * Starting Tvheadend tvheadend
May 15 13:57:49 flanders tvheadend¹²³⁷: main: Log started
May 15 13:57:49 flanders systemd¹: Started tvheadend.service.
May 15 13:57:49 flanders tvheadend⁸⁷⁷: ...done.
May 15 13:57:49 flanders tvheadend¹²³⁷: http: Starting HTTP server 0.0.0.0:9981
May 15 13:57:49 flanders tvheadend¹²³⁷: htsp: Starting HTSP server 0.0.0.0:9982
May 15 13:57:52 flanders tvheadend¹²³⁷: config: backup: migrating config from 4.2.1-29~g21c97e1 (running 4.2.1-51~g04b6e3c)
May 15 13:57:52 flanders tvheadend¹²³⁷: config: backup: running, output file /home/hts/.hts/tvheadend/backup/4.2.1-29~g21c97e1.tar.bz2
May 15 13:57:52 flanders tvheadend¹²³⁷: spawn: Executing "/bin/tar"
May 15 13:57:53 flanders tvheadend¹²³⁷: spawn: /bin/tar: ./input/dvb/networks/c5ade558437dac80cba4d79b6b7f6b8e/muxes/kmsb/config: Cannot open: Permission denied
May 15 13:57:53 flanders tvheadend¹²³⁷: spawn: /bin/tar: ./input/dvb/networks/c5ade558437dac80cba4d79b6b7f6b8e/muxes/kmsb/services/4403576ecdc0d935a30d7a3ca665df28: Cannot open: Permission denied
May 15 13:57:53 flanders tvheadend¹²³⁷: spawn: /bin/tar: ./input/dvb/networks/c5ade558437dac80cba4d79b6b7f6b8e/muxes/kmsb/services/3d7f901ba550307d6f52754c2a5ed23b: Cannot open: Permission denied
May 15 13:57:53 flanders tvheadend¹²³⁷: spawn: /bin/tar: ./input/dvb/networks/c5ade558437dac80cba4d79b6b7f6b8e/muxes/kmsb/services/34554366edd3c7d5f46a205f14d6aae9: Cannot open: Permission denied
May 15 13:57:55 flanders tvheadend¹²³⁷: spawn: /bin/tar: Exiting with failure status due to previous errors
May 15 13:57:55 flanders tvheadend¹²³⁷: config: backup: completed
May 15 13:57:55 flanders tvheadend¹²³⁷: config: command '/bin/tar cjf /home/hts/.hts/tvheadend/backup/4.2.1-29~g21c97e1.tar.bz2 --exclude backup --exclude epggrab/*.sock --exclude timeshift/buffer .' returned error code 2
May 15 13:57:55 flanders tvheadend¹²³⁷: config: executed in directory '/home/hts/.hts/tvheadend'
May 15 13:57:55 flanders tvheadend¹²³⁷: config: please, do not report this as an error, you may use --nobackup option
May 15 13:57:55 flanders tvheadend¹²³⁷: config: ... or run the above command in the printed directory
May 15 13:57:55 flanders tvheadend¹²³⁷: config: ... using the same user/group as for the tvheadend executable
May 15 13:57:55 flanders tvheadend¹²³⁷: config: ... to check the reason for the unfinished backup
May 15 13:57:55 flanders tvheadend¹²³⁷: config: backup: fatal error