@JJTittles; I can assure you that the plotting function works just fine. Here is a chart that I just ran.
Screenshot 2024年06月22日 110916

I'm running the backtesting.py library from pycharm without any problems, as well as a range of many other bokeh plots. If you'd like help getting it working, you're going to need to do better than "your thing doesn't work, so I'm throwing my toys out of the cot". If you can describe what you've tried, what you're seeing and what errors are appearing, it might be possible for others to offer their free time to assist you.

Hey @JJTittles; no worries. Writing code can be a lonely and frustrating road. I'm a complete noob, not a software eng, so I understand how you feel.

Noting the above...your error looks like its coming from Bokeh itself. If you navigate through backtesting.py to _plotting.py in your IDE, on about line 250 you'll see something like:

if is_datetime_index: fig_ohlc.xaxis.formatter = CustomJSTickFormatter( args=dict(axis=fig_ohlc.xaxis[0], formatter=DatetimeTickFormatter(days=['%d %b', '%a %d'] months=['%m/%Y', "%b'%y"]), source=source)

Bokeh now doesn't like inputs to DatetimeTickFormatter to be a list.

Go into this line of code, comment out the list input (so you can go back) and instead write:
formatter=DatetimeTickFormatter(days='%a, %d %b', # ["%d %b', '%a %d"] months='%m/%Y'), # ["%m/%Y', "%b'%y"]

This should work for you. Let me know how you go. As a tip, I paid the 10ドル/mth for GitHub CoPilot...for someone like me who is clueless with code, its saved a lot of time. Works directly from with pycharm, or whatever IDE you use.