Two months ago Google launched the new disavow link tool in the new Google Search Console. Now, Google is sunsetting the old tool in just a few days from now. On January 19, 2021, Google said it will be removing access to the old version of this tool.
Here is a link to the old version which reads "Important: This report won't be available after Jan 19, 2021. Please use the new Disavow Links report instead."
Here is a screen shot:
The new version is available over here and it is prettier with the added the ability to download the file as text and added more errors to the error reports for uploaded files.
I don't think anyone will miss the old version.
Here is John Mueller on why it is going away:
The new one has been out for a while, they do the same thing.
— 🍌 John 🍌 (@JohnMu) January 14, 2021
Forum discussion at Twitter.