Unable to start dropbox in Ubuntu 20.04

Hi, I am unable to start the dropbox in Ubuntu 20.04 with Headless Mode with the following errors. I had read through all the forums and documents to find out the solution in order to fix this error but now lucks.

I had already perform `dropbox start` as root but still obtains:

Couldn't start Dropbox.
This is usually because of a permissions error. Storing your home folder on a network share can also cause an error.

Get more help at https://www.dropbox.com/c/help/permissions_error

The log of /tmp/dropbox_errorf0tk7axj.txt are shown below: 

bn.BUILD_KEY: Dropbox
bn.VERSION: 131.4.3968
bn.constants.WINDOWS_SHELL_EXT_VERSION: 48
bn.is_frozen: True
machine_id: 20210623-1124-0478-1463-487467590001
pid: 30950
ppid: 1
ppid exe: '/usr/lib/systemd/systemd'
uid: 0
user_info: pwd.struct_passwd(pw_name='root', pw_passwd='x', pw_uid=0, pw_gid=0, pw_gecos='root', pw_dir='/root', pw_shell='/bin/bash')
effective_user_info: pwd.struct_passwd(pw_name='root', pw_passwd='x', pw_uid=0, pw_gid=0, pw_gecos='root', pw_dir='/root', pw_shell='/bin/bash')
euid: 0
gid: 0
egid: 0
group_info: grp.struct_group(gr_name='root', gr_passwd='x', gr_gid=0, gr_mem=[])
effective_group_info: grp.struct_group(gr_name='root', gr_passwd='x', gr_gid=0, gr_mem=[])
LD_LIBRARY_PATH: None
cwd: '/root'
     real_path='/root'
                mode=0o40700    uid=0   gid=0
     parent     mode=0o40755    uid=0   gid=0
HOME: '/root'
appdata: '/root/.dropbox/instance5'
         real_path='/root/.dropbox/instance5'
                mode=0o40700    uid=0   gid=0
         parent mode=0o40755    uid=0   gid=0
dropbox_path: None
                        not found
              parent    not found
sys_executable: '/root/.dropbox-dist/dropbox-lnx.x86_64-131.4.3968/dropbox'
                real_path='/root/.dropbox-dist/dropbox-lnx.x86_64-131.4.3968/dropbox'
                        mode=0o100755   uid=0   gid=0
                parent  mode=0o40755    uid=0   gid=0
trace.__file__: '/root/.dropbox-dist/dropbox-lnx.x86_64-131.4.3968/python-packages.zip/dropbox/client/ui/common/boot_error.pyc'
                real_path='/root/.dropbox-dist/dropbox-lnx.x86_64-131.4.3968/python-packages.zip/dropbox/client/ui/common/boot_error.pyc'
                        not found
                parent  not found
tempdir: '/tmp'
         real_path='/tmp'
                mode=0o41777    uid=0   gid=0
         parent mode=0o40755    uid=0   gid=0
Traceback (most recent call last):
  File "dropbox/client/main.pyc", line 5397, in _setup_root_for_account
AssertionError: fresh link yet no preferences