NVim blocks while update is in progress

One of the plugins I am using had its github repo removed.

Running PackerSync will now block nvim for minutes (or maybe even forever? I do not have the patience to find out;-), while it is trying to update the repository!

All plugins updated but the one where I can not find the repository anymore. There is a line at the top of the update window, which says Username for 'https://github.com' so git might be waiting for input? I can not find any way to interact with the window and type anything that would let me continue.

Any ideas? I had to kill nvim completely to get out again and that is not nice.