New Documents added to Library requiring Title even though it is not marked as Required before they can be Checked In

Question

I have a Subsite with many similar Libraries with Require Check Out enabled on all. This subsite has been somewhat problematic in general and it may be that I need to recreate and move everything anyway, though I am hoping not to need to resort to that. The weird thing that has only begun to happen recently, is I get an error message everytime I try checking in a new document I've added:

"Sorry, something went wrong. You must fill out all required properties before checking in this document"

If I try to edit the document properties I notice that Title (default column unable to be deleted) appears and is both empty and starred for every new document I add. From reading elsewhere, both of these are attributed to documents having a required field at Check In, but if I view the Library Properties none of the Columns are marked as Required. This has made mass Check-Ins impossible (I have a flattened view in each library so users can check in multiple documents simultaneously) and made checking in documents far more cumbersome. I'm wondering if there is another feature/setting I am not considering that may be creating this Check In error, or if this is an issue others have dealt with before.

Thanks!

Answer 1

I feel stupid answering my own question seven hours after posting, but in my efforts on another Subsite to Allow management of content types (Under Advanced Settings of a List) so I could hide the default column I accidently altered this content type on the top level site. I changed the Status of the Document content type to Hidden and saved. When I noticed that I was affecting a global change rather than a local one I reset the Status to Required and proceeded to Uncheck Allow management of content types lower down, but the global change had already taken effect and this was the reason I presume why everything I added to the website now was requiring a title before Check-In. Once I realized this I returned to the global Site Content Types settings and set it to Optional which finally removed this burden.