The version I have installed is tvheadend: version 4.3^20230408gitf32c7c5-1.fc38
I first of all stopped the service, restarted it and then ran the initialisation command
Here is the output from the sequence:
[root@saruman root]# systemctl start tvheadend.service
[root@saruman root]# tvheadend --noacl
2023-10-27 18:19:17.616 [ INFO] main: Log started
2023-10-27 18:19:17.616 [ INFO] tcp: No systemd socket: creating a new one
2023-10-27 18:19:17.616 [ ERROR] tcp: bind:
:9981: Address already in use
2023-10-27 18:19:17.616 [ INFO] tcp: No systemd socket: creating a new one
2023-10-27 18:19:17.616 [ ERROR] tcp: bind: :9982: Address already in use
2023-10-27 18:19:17.641 [ INFO] config: loaded
2023-10-27 18:19:17.642 [ INFO] config: scanfile (re)initialization with path <none>
2023-10-27 18:19:17.642 [ INFO] transcode: 'video' context type registered
2023-10-27 18:19:17.642 [ INFO] transcode: 'audio' context type registered
2023-10-27 18:19:17.642 [ INFO] transcode: '&TVHH264Decoder' decoder helper registered
2023-10-27 18:19:17.642 [ INFO] transcode: '&TVHTHEORADecoder' decoder helper registered
2023-10-27 18:19:17.642 [ INFO] transcode: '&TVHAACDecoder' decoder helper registered
2023-10-27 18:19:17.642 [ INFO] transcode: '&TVHVORBISDecoder' decoder helper registered
2023-10-27 18:19:17.642 [ INFO] transcode: '&TVHOPUSDecoder' decoder helper registered
2023-10-27 18:19:17.642 [ INFO] transcode: '&TVHMPEG2VIDEOEncoder' encoder helper registered
2023-10-27 18:19:17.642 [ INFO] transcode: '&TVHH264Encoder' encoder helper registered
2023-10-27 18:19:17.642 [ INFO] transcode: '&TVHHEVCEncoder' encoder helper registered
2023-10-27 18:19:17.642 [ INFO] transcode: '&TVHAACEncoder' encoder helper registered
2023-10-27 18:19:17.644 [ INFO] codec: 'mpeg2video' encoder registered
2023-10-27 18:19:17.644 [ INFO] codec: 'mp2' encoder registered
2023-10-27 18:19:17.644 [ INFO] codec: 'aac' encoder registered
2023-10-27 18:19:17.644 [ INFO] codec: 'vorbis' encoder registered
2023-10-27 18:19:17.644 [ INFO] codec: 'flac' encoder registered
2023-10-27 18:19:17.644 [ INFO] codec: 'libx264' encoder registered
2023-10-27 18:19:17.644 [ INFO] codec: 'libx265' encoder registered
2023-10-27 18:19:17.644 [ INFO] codec: 'libvpx' encoder registered
2023-10-27 18:19:17.644 [ INFO] codec: 'libvpx-vp9' encoder registered
2023-10-27 18:19:17.644 [ INFO] codec: 'libtheora' encoder registered
2023-10-27 18:19:17.644 [ INFO] codec: 'libvorbis' encoder registered
2023-10-27 18:19:17.644 [ INFO] codec: 'libfdk_aac' encoder registered
2023-10-27 18:19:17.644 [ INFO] codec: 'libopus' encoder registered
2023-10-27 18:19:17.644 [ INFO] codec: 'h264_vaapi' encoder registered
2023-10-27 18:19:17.644 [ INFO] codec: 'hevc_vaapi' encoder registered
2023-10-27 18:19:17.644 [ INFO] codec: 'vp8_vaapi' encoder registered
2023-10-27 18:19:17.644 [ INFO] codec: 'vp9_vaapi' encoder registered
2023-10-27 18:19:17.644 [ INFO] codec: 'webtv-vp8' codec profile created
2023-10-27 18:19:17.644 [ INFO] codec: 'webtv-h264' codec profile created
2023-10-27 18:19:17.644 [ INFO] codec: 'webtv-vorbis' codec profile created
2023-10-27 18:19:17.644 [ INFO] codec: 'webtv-aac' codec profile created
2023-10-27 18:19:17.646 [ INFO] descrambler: adding CAID 2600/FFFF as ConstCW interval 10000ms pc 20 ep default (BISS)
2023-10-27 18:19:17.646 [ INFO] descrambler: adding CAID 0E00/FFFF as MultiPID interval 1000ms pc 2 ep default (PowerVu)
2023-10-27 18:19:17.648 [ INFO] iptv: Using 2 input thread(s)
2023-10-27 18:19:18.042 [ INFO] scanfile: DVB-S - loaded 1 regions with 272 networks
2023-10-27 18:19:18.042 [ INFO] scanfile: DVB-T - loaded 44 regions with 1080 networks
2023-10-27 18:19:18.042 [ INFO] scanfile: DVB-C - loaded 18 regions with 62 networks
2023-10-27 18:19:18.042 [ INFO] scanfile: ATSC-T - loaded 2 regions with 13 networks
2023-10-27 18:19:18.042 [ INFO] scanfile: ATSC-C - loaded 2 regions with 6 networks
2023-10-27 18:19:18.042 [ INFO] scanfile: ISDB-T - loaded 2 regions with 2544 networks
2023-10-27 18:19:19.655 [ ERROR] linuxdvb: unable to open /dev/dvb/adapter1/frontend0
2023-10-27 18:19:21.659 [ ERROR] linuxdvb: unable to open /dev/dvb/adapter0/frontend0
2023-10-27 18:19:21.662 [ INFO] dvr: Creating new configuration ''
2023-10-27 18:19:21.662 [WARNING] access: Access control checking disabled
2023-10-27 18:19:21.664 [ INFO] epggrab: module uk_freesat created
2023-10-27 18:19:21.664 [ INFO] epggrab: module uk_freesat_eit created
2023-10-27 18:19:21.664 [ INFO] epggrab: module uk_freeview created
2023-10-27 18:19:21.664 [ INFO] epggrab: module nz_freeview2 created
2023-10-27 18:19:21.664 [ INFO] epggrab: module nz_freeview1 created
2023-10-27 18:19:21.665 [ INFO] epggrab: module viasat_baltic created
2023-10-27 18:19:21.665 [ INFO] epggrab: module Bulsatcom_39E created
2023-10-27 18:19:21.665 [ INFO] epggrab: module uk_cable_virgin created
2023-10-27 18:19:21.665 [ INFO] epggrab: module eit created
2023-10-27 18:19:21.665 [ INFO] epggrab: module psip created
2023-10-27 18:19:21.671 [ INFO] epggrab: module opentv-ausat created
2023-10-27 18:19:21.672 [ INFO] epggrab: module opentv-skyit created
2023-10-27 18:19:21.673 [ INFO] epggrab: module opentv-skynz created
2023-10-27 18:19:21.674 [ INFO] epggrab: module opentv-skyuk created
2023-10-27 18:19:21.674 [ INFO] epggrab: module xmltv created
2023-10-27 18:19:21.677 [ INFO] tbl-eit: module eit - scraper disabled by config
2023-10-27 18:19:21.677 [ INFO] epgdb: gzip format detected, inflating (ratio 138.6% deflated size 79)
2023-10-27 18:19:21.677 [ INFO] epgdb: parsing 57 bytes
2023-10-27 18:19:21.678 [ INFO] epgdb: loaded v3
2023-10-27 18:19:21.678 [ INFO] epgdb: config 1
2023-10-27 18:19:21.678 [ INFO] epgdb: broadcasts 0
2023-10-27 18:19:21.679 [ INFO] dvr: Purging obsolete autorec entries for current schedule
2023-10-27 18:19:21.680 [ NOTICE] START: HTS Tvheadend version 4.3^20230408gitf32c7c5-1.fc38 started, running as PID:273667 UID:0 GID:0, CWD:/export/root CNF:/root/.hts/tvheadend
2023-10-27 18:19:22.439 [ INFO] avahi: Service 'Tvheadend' successfully established.
When I then try to login with root and the password, it responds with 403 Forbidden.