AttributeError: 'NoneType' object has no attribute 'lower'

[Dezaku]

23:13:57 finding a post to re-post
23:13:57 picking a random subreddit
23:13:57 checking subreddit: danganronpa
23:13:57 searching post in sub: danganronpa
23:13:57 pushshift-url: https://api.pushshift.io/reddit/search/submission/?subreddit=danganronpa&before=1637014437&after=1636928037&score>=5000&limit=1&author!=[deleted]&selftext:not=[deleted]
23:13:58 reposting post: qu18sn
Traceback (most recent call last):
File "/home/dezaku/reddit-karma-farming-bot/./src/init.py", line 12, in
bot.run()
File "/home/dezaku/reddit-karma-farming-bot/src/bot.py", line 10, in run
reddit.run()
File "/home/dezaku/reddit-karma-farming-bot/src/bots/reddit/bot.py", line 65, in run
self.tick()
File "/home/dezaku/reddit-karma-farming-bot/src/bots/reddit/bot.py", line 60, in tick
action.call()
File "/home/dezaku/reddit-karma-farming-bot/src/bots/reddit/actions/post_actions.py", line 122, in repost
sub = self.rapi.subreddit(self.crosspost(sub.display_name))
File "/home/dezaku/reddit-karma-farming-bot/.venv/lib/python3.10/site-packages/praw/models/helpers.py", line 321, in call
lower_name = display_name.lower()
AttributeError: 'NoneType' object has no attribute 'lower'