E444: Cannot close last window

[YodaEmbedding]

Steps to reproduce

Minimal .vimrc:

" ~/vimrc_minimal
call plug#begin('~/.local/share/nvim/plugged')
Plug 'dstein64/nvim-scrollview'
call plug#end()

Run the following:

mkdir -p root/subdir
cd root
touch a subdir/b
vim -u ~/vimrc_minimal

Inside vim, execute the following:

:e a<CR>
:e subdir/b<CR>
200OHello, world!<Esc>
:w<CR>
:bd<CR>

We should now see the error message:

E444: Cannot close last window
E444: Cannot close last window
Press ENTER or type command to continue

[dstein64]

Thanks for reporting this @YodaEmbedding!

I've reproduced the issue outside the context of nvim-scrollview and reported the issue to the Neovim project.
neovim/neovim#13628

[dstein64]

This problem is now documented under :help scrollview-issues, along with two proposed workarounds:

• Workaround 1: Use :only or <ctrl-w>o, which has the side-effect of closing all floating windows (including scrollbars). A subsequent :bdelete command works without error.
• Workaround 2: Create a Bdelete command that avoids the issue.

  command Bdelete
        \ silent! ScrollViewDisable
        \ | bdelete
        \ | silent! ScrollViewEnable

(workaround 2 requires a plugin update)

[dstein64]

This is fixed as of Neovim #17806.