Question: Why is the File button missing on some cases on the Case Overviews and Cases page?
Answer: That is because of a limitation in the eFileTexas system for certain jurisdictions. FileTime provides you the data to view the case service contacts, case data, etc. but it is not the official eFileTexas data. After your first accepted submission in the case you will have access to the File button.
In those instances where the File button is not displayed you will need to search for the case using the Search fields at the top of the Case Overviews and Cases pages.