Error on saving/opening a session

[morhaham]

first thing first, great dotfiles, thanks for that.

<Leader> / s c(s) <CR> saves/opens the session but produces this message:

Error detected while processing User Autocommands for "SessionSavePre":
Error executing lua callback: ...e/pack/packer/start/barbar.nvim/lua/bufferline/state.lua:737: bad argument #1 to 'insert' (table expected, got nil)
stack traceback:
        [C]: in function 'insert'
        ...e/pack/packer/start/barbar.nvim/lua/bufferline/state.lua:737: in function 'on_pre_save'
        ...im/site/pack/packer/start/barbar.nvim/lua/bufferline.lua:84: in function <...im/site/pack/packer/start/barbar.nvim/lua/bufferline.lua:84>
        [C]: in function 'nvim_exec_autocmds'
        ...art/neovim-session-manager/lua/session_manager/utils.lua:84: in function 'save_session'
        ...tart/neovim-session-manager/lua/session_manager/init.lua:49: in function 'save_current_session'
        ...tart/neovim-session-manager/lua/session_manager/init.lua:87: in function 'autosave_session'
        ...tart/neovim-session-manager/lua/session_manager/init.lua:29: in function 'on_choice'
        .../packer/start/dressing.nvim/lua/dressing/select/init.lua:69: in function ''
        vim/_editor.lua: in function <vim/_editor.lua:0>