File with special characters is returning error

Hi, I’m trying to extract the content from the Wikipedia page Sun - Wikipedia, break them down into sentences and upload it as a JSONL file to OpenAI. The file gets uploaded successfully but when I try to ask a question from it, it says that something went wrong while processing the file. I suspect this happens due to some of the special characters(Greek letters) present in the content.

Can someone help me out with this? Thanks in advance.