Nextcloud to Collabora online not load the documents

I installed Collabora Online 4.0.4 next to nginx-nextcloud, but unfortunately it doesn’t want to load the documents. Neither existing nor when I create a new one. I am attaching a picture of the error phenomenon.

Running systemctl status loolwsd output:

loolwsd.service - Collabora Online WebSocket Daemon
     Loaded: loaded (/lib/systemd/system/loolwsd.service; enabled; vendor preset: enabled)
     Active: active (running) since Fri 2021-04-16 18:59:34 CEST; 8s ago
   Main PID: 3101 (loolwsd)
      Tasks: 7 (limit: 3409)
     Memory: 143.4M
     CGroup: /system.slice/loolwsd.service
             ├─3101 /usr/bin/loolwsd --version --o:sys_template_path=/opt/lool/systemplate --o:child_root_path=/opt/lool/child-roots --o:file_server_root_path=/usr/share/loolwsd
             ├─3129 /usr/bin/loolforkit          --losubpath=lo --systemplate=/opt/lool/systemplate --lotemplate=/opt/collaboraoffice6.4 --childroot=/opt/lool/child-roots/ --clientport=9980 --masterport=loolwsd-MixC4Rkm --rlimits=limit_virt_mem_mb:0;limit_stack_mem_kb:8000;limit_file_size_mb:0;limit_num_open_files:0 --version --ui=classic
             └─3131 /usr/bin/loolforkit          --losubpath=lo --systemplate=/opt/lool/systemplate --lotemplate=/opt/collaboraoffice6.4 --childroot=/opt/lool/child-roots/ --clientport=9980 --masterport=loolwsd-MixC4Rkm --rlimits=limit_virt_mem_mb:0;limit_stack_mem_kb:8000;limit_file_size_mb:0;limit_num_open_files:0 --version --ui=classic

> Apr 16 18:59:42 <nas-name> loolwsd[3101]: wsd-03101-03128 2021-04-16 16:59:42.567009 [ prisoner_poll ] DBG  Removing socket #18 (of 3) from prisoner_poll| net/Socket.cpp:321
Apr 16 18:59:42 <nas-name> loolwsd[3101]: wsd-03101-03128 2021-04-16 16:59:42.567025 [ prisoner_poll ] DBG  #18 Thread affinity set to 0 (was 0x7fe6b991b700).| ./net/Socket.hpp:300
Apr 16 18:59:42 <nas-name> loolwsd[3101]: wsd-03101-03128 2021-04-16 16:59:42.567042 [ prisoner_poll ] TRC  Calling addNewChild in disposition's move thing to add to NewChildren| wsd/LOOLWSD.cpp:2219
Apr 16 18:59:42 <nas-name> loolwsd[3101]: wsd-03101-03128 2021-04-16 16:59:42.567057 [ prisoner_poll ] TRC  Adding one child to NewChildren| wsd/LOOLWSD.cpp:475
Apr 16 18:59:42 <nas-name> loolwsd[3101]: wsd-03101-03128 2021-04-16 16:59:42.567072 [ prisoner_poll ] INF  Have 1 spare child after adding [3131].| wsd/LOOLWSD.cpp:478
Apr 16 18:59:42 <nas-name> loolwsd[3101]: wsd-03101-03128 2021-04-16 16:59:42.567087 [ prisoner_poll ] TRC  Notifying NewChildrenCV| wsd/LOOLWSD.cpp:482
Apr 16 18:59:42 <nas-name> loolwsd[3101]: wsd-03101-03128 2021-04-16 16:59:42.567132 [ prisoner_poll ] TRC  ppoll start, timeoutMicroS: 5000000 size 2| net/Socket.cpp:217
Apr 16 18:59:42 <nas-name> loolwsd[3101]: wsd-03101-03101 2021-04-16 16:59:42.567146 [ loolwsd ] TRC  Have 1 new children.| wsd/LOOLWSD.cpp:4032
Apr 16 18:59:42 <nas-name> loolwsd[3101]: wsd-03101-03101 2021-04-16 16:59:42.567185 [ loolwsd ] INF  WSD initialization complete: setting log-level to [warning] as configured.| wsd/LOOLWSD.cpp:4039
Apr 16 18:59:42 <nas-name> loolwsd[3101]: Ready to accept connections on port 9980.

What might be the proble?

Please help!

I found the solution, it works.
Ubuntu server 20.04 - Nginx - Nextcloud - Collabora (without docker)

Solved