Error on page 404 (non-existent address)

Hello. I recently encountered an error. If you type a non-existent address in the address bar, then on page 404, in addition to the text “Not found”, it also gives a list of errors of this type: “Fatal error: Uncaught Error: Call to undefined function faith_categorized_blog() in ” and then a list of site paths in which, including, there is also a way for 404 themes.
Tell me, can this be fixed somehow at the theme level, or is this a bug specifically on my site?
I tested such requests a couple of months ago and everything was fine. I don’t know what caused this, a wordpress update or a theme update.

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