Getting this error. Can someone help please.

PS C:\Users\dhruv\Downloads> otree zipserver
Running uvx-Project.otreezip
Traceback (most recent call last):
  File "C:\Users\dhruv\AppData\Local\Programs\Python\Python37\Scripts\otree-script.py", line 11, in <module>
    load_entry_point('otree==5.10.4', 'console_scripts', 'otree')()
  File "c:\users\dhruv\appdata\local\programs\python\python37\lib\site-packages\otree\main.py", line 108, in execute_from_command_line
    setup()
  File "c:\users\dhruv\appdata\local\programs\python\python37\lib\site-packages\otree\main.py", line 139, in setup
    init_orm()
  File "c:\users\dhruv\appdata\local\programs\python\python37\lib\site-packages\otree\database.py", line 323, in init_orm
    configure_mappers()
  File "c:\users\dhruv\appdata\local\programs\python\python37\lib\site-packages\sqlalchemy\orm\mapper.py", line 3299, in configure_mappers
    mapper._post_configure_properties()
  File "c:\users\dhruv\appdata\local\programs\python\python37\lib\site-packages\sqlalchemy\orm\mapper.py", line 1965, in _post_configure_properties
    prop.init()
  File "c:\users\dhruv\appdata\local\programs\python\python37\lib\site-packages\sqlalchemy\orm\interfaces.py", line 197, in init
    self.do_init()
  File "c:\users\dhruv\appdata\local\programs\python\python37\lib\site-packages\sqlalchemy\orm\relationships.py", line 2081, in do_init
    self._generate_backref()
  File "c:\users\dhruv\appdata\local\programs\python\python37\lib\site-packages\sqlalchemy\orm\relationships.py", line 2395, in _generate_backref
    self._add_reverse_property(self.back_populates)
  File "c:\users\dhruv\appdata\local\programs\python\python37\lib\site-packages\sqlalchemy\orm\relationships.py", line 2011, in _add_reverse_property
    self._check_sync_backref(other, self)
  File "c:\users\dhruv\appdata\local\programs\python\python37\lib\site-packages\sqlalchemy\orm\relationships.py", line 1988, in _check_sync_backref
    if rel_a.viewonly and rel_b.sync_backref:
  File "c:\users\dhruv\appdata\local\programs\python\python37\lib\site-packages\sqlalchemy\util\langhelpers.py", line 987, in __getattr__
    return self._fallback_getattr(key)
  File "c:\users\dhruv\appdata\local\programs\python\python37\lib\site-packages\sqlalchemy\util\langhelpers.py", line 961, in _fallback_getattr
    raise AttributeError(key)
AttributeError: viewonly

Can you attach the .otreezip file here, or send it to chris@otree.org?

Sent to chris@otree.org

Hi, this error occurred because your Player model had a field called 'group'. That is already a built-in field name, so it cannot be redefined (same with subsession, session, etc). In a future version I'll block that name from being used.
Thanks,
Chris