Server 8.0.x - seahub.sh Error:Seahub failed to start after update lubuntu 20.04

Hello 
i need help  plz. 

After lubuntu 18.04 to 20.04 
**seahub.sh give an error**
LC_ALL is not set in ENV, set to en_US.UTF-8
Starting seahub at port 8000 ...
Error:Seahub failed to start.
Please try to run "./seahub.sh start" again

**seafile.sh starts**
Starting seafile server, please wait ...
** Message: 16:59:03.184: seafile-controller.c(536): No seafevents.

Seafile server started

Done.


**i use:**
seafile server 8.0.x
mysql-server on nginx with ssl certificate

**seahub log**
empty

**controller log**
2021-05-27 16:59:03 seafile-controller.c(190): starting seaf-server ...
2021-05-27 16:59:03 seafile-controller.c(81): spawn_process: seaf-server -F /home/ich/haiwen/conf -c /home/ich/haiwen/ccnet -d /home/ich/haiwen/seafile-data -l /home/ich/haiwen/logs/seafile.log -P /home/ich/haiwen/pids/seaf-server.pid -p /home/ich/haiwen/seafile-server-8.0.5/runtime
2021-05-27 16:59:03 seafile-controller.c(115): spawned seaf-server, pid 382078
2021-05-27 16:59:13 seafile-controller.c(416): pid file /home/ich/haiwen/pids/seafdav.pid does not exist
2021-05-27 16:59:13 seafile-controller.c(443): seafdav need restart...
2021-05-27 16:59:13 seafile-controller.c(81): spawn_process: /usr/bin/python3 -m wsgidav.server.server_cli --server gunicorn --root / --log-file /home/ich/haiwen/logs/seafdav.log --pid /home/ich/haiwen/pids/seafdav.pid --port 8080 --host 0.0.0.0
2021-05-27 16:59:13 seafile-controller.c(115): spawned /usr/bin/python3, pid 382126

**seafdav log**
2021-05-27 16:59:14.228 - <140187041535808> wsgidav.dc.seahub_db        INFO    :  Init seahub database...
2021-05-27 16:59:15.350 - <140187041535808> wsgidav.wsgidav_app         INFO    :  WsgiDAV/3.0.4 Python/3.8.5 Linux-5.4.0-73-generic-x86_64-with-glibc2.29
2021-05-27 16:59:15.350 - <140187041535808> wsgidav.wsgidav_app         INFO    :  Lock manager:      LockManager(LockStorageDict)
2021-05-27 16:59:15.350 - <140187041535808> wsgidav.wsgidav_app         INFO    :  Property manager:  None
2021-05-27 16:59:15.350 - <140187041535808> wsgidav.wsgidav_app         INFO    :  Domain controller: SeafileDomainController()
2021-05-27 16:59:15.350 - <140187041535808> wsgidav.wsgidav_app         INFO    :  Registered DAV providers by route:
2021-05-27 16:59:15.351 - <140187041535808> wsgidav.wsgidav_app         INFO    :    - '/:dir_browser': FilesystemProvider for path '/home/ich/haiwen/seafile-server-8.0.5/seahub/thirdpart/wsgidav/dir_browser/htdocs' (Read-Only)
2021-05-27 16:59:15.351 - <140187041535808> wsgidav.wsgidav_app         INFO    :    - '/seafdav': SeafileProvider for Seafile (Read-Write)
2021-05-27 16:59:15.351 - <140187041535808> wsgidav.wsgidav_app         WARNING :  Basic authentication is enabled: It is highly recommended to enable SSL.
2021-05-27 16:59:15.351 - <140187041535808> wsgidav                     WARNING :  Could not import lxml: using xml instead (up to 10% slower). Consider `pip install lxml`(see https://pypi.python.org/pypi/lxml).


**seafile log**
2021-05-27 16:59:03 socket file exists, delete it anyway
2021-05-27 16:59:03 ../common/seaf-utils.c(333): Use database Mysql
2021-05-27 16:59:03 http-server.c(192): fileserver: worker_threads = 10
2021-05-27 16:59:03 http-server.c(207): fileserver: fixed_block_size = 8388608
2021-05-27 16:59:03 http-server.c(222): fileserver: web_token_expire_time = 3600
2021-05-27 16:59:03 http-server.c(237): fileserver: max_indexing_threads = 1
2021-05-27 16:59:03 http-server.c(252): fileserver: max_index_processing_threads= 3
2021-05-27 16:59:03 http-server.c(274): fileserver: cluster_shared_temp_file_mode = 600
2021-05-27 17:00:15 start to serve on pipe client

I’m not sure it’s related, on 7.1.4 I had a similar problem. Using ./seahub.sh start-fastcgi I was able to get a more verbose output why seahub failed to start and was able to troubleshoot from there.
For the forum thread, see here: Ubuntu Upgrade to 20.04 broke Seahub (ARM)

Maybe it’s something related for you or helps you find the correct direction to troubleshoot your problem

This post seems similar to your situation. I recently encountered a problem upgrading to Ubuntu 20.04 and it was the captcha even though it was previously installed and running fine.

sudo apt -y install python3 python3-pip python3-pil python3-ldap python3-urllib3 libpython3.8 python3-setuptools python3-mysqldb python3-memcache python3-requests ffmpeg

sudo apt install python3-django-captcha

thx for help

after apt-get purge nginx, reinstall and reconfig nginx

yes, seahub works

i think some packages and ngnix was wrong