Power Query Refresh

Hello,

So I have a pbix file that refreshes with new data each day, and when I click refresh in Power BI, there pops up this error:

I just don't understand what is causing this error, since nothng in the code for the query references another query or step. Here is what the steps are in advanced editor:

Another thing is that it doesn't always pop up and give an error, sometimes it runs smoothly refreshes free of errors and other times it gives me errors, so I would definitely appreciate some insight into how to alleviate all errors 100% of the time.

Unfortunately I can't share my pbix file, as there is sensitive data in there, so I apologize. Thank you in advance!