Bad Request: Request Line is too large

I tried forking a query and it seems that we i could not create the fork due to this error.
My query is currently ~70 lines and I don’t understand the error.

The length of the query isn’t the issue. You can fork queries that are thousands of lines long.

I think the issue is your server, not Redash itself. Are you running with Apache? Perhaps this github issue with the same error will help you.