Hi! I am trying to deploy an otree/heroku app on prolific.

I have so far created a player variable: prolific_id = models.StringField()

Additionally on one of the earlier apps, I set the prolific_id player variable to the participant.label and adjusted the link on prolific from PROLIFIC_ID to participant_label.

@staticmethod
    def before_next_page(self, timeout_happened):
        self.prolific_id = self.participant.label

Unfortunately, I get the following error (below). Any help would be appreciated. 

Failed to create session: (sqlite3.OperationalError) table otree_participant has no column named _waitpage_is_connected [SQL: INSERT INTO otree_participant (_vars, session_id, label, id_in_session, payoff, time_started_utc, mturk_assignment_id, mturk_worker_id, _index_in_pages, _monitor_note, code, _session_code, visited, _last_page_timestamp, _last_request_timestamp, is_on_wait_page, _current_page_name, _current_app_name, _round_number, _current_form_page_url, _max_page_index, _is_bot, is_browser_bot, _timeout_expiration_time, _timeout_page_index, _waitpage_is_connected, _waitpage_tab_hidden, _gbat_page_index, _gbat_grouped) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)] [parameters: ('gAR9lC4=\n', 56, None, 1, '0', None, None, None, 0, None, '8nhm9dvm', 't8nzlwc5', 0, None, None, 0, None, None, None, None, None, 0, 0, None, None, 0, 0, None, None)] (Background on this error at: http://sqlalche.me/e/13/e3q8)
Traceback (most recent call last):
  File "/app/.heroku/python/lib/python3.9/site-packages/sqlalchemy/engine/base.py", line 1276, in _execute_context
    self.dialect.do_execute(
  File "/app/.heroku/python/lib/python3.9/site-packages/sqlalchemy/engine/default.py", line 609, in do_execute
    cursor.execute(statement, parameters)
sqlite3.OperationalError: table otree_participant has no column named _waitpage_is_connected