Are you using any mods? Because the fix should only be present if you are using a mod or my bugfix patch.(Edit: or if you added it yourself, in which case you made a mistake or used a low quality text editor) If you aren't using my patch, I recommend getting it from Discord as stated in a post above.
If the error message does not exactly match the one in the first post, then please post it here.
You cannot have both the working fix and the error, so one of those is different.