Interface Pages Record Editing for Users

[rfcontractor]

I spent hours adding hundreds of editable fields to an interface. The associated table is near the 500 column limit (476).

75% of the way through adding the fields I started getting the error "Sorry, your request conflicted with another change and was reverted." whenever I added or edited something on the interface.

Has anyone else faced this? Am I reaching a secret interface field limit I don't know about? 

I really do not want to spend hours rebuilding this interface from scratch just to get the same error again. 

I tried: 

-having a collaborator edit, same error.

-making sure my permissions are set to creator

-logging in and out + clearing cache

-creating a new user and editing with that account

-two different web browsers

-duplicating the interface and editing that one

-publishing and unpublishing the interface