合并前四个commit message

1. git rebase -i 第五个commitID

2. 将前四个commit message前的pick改为 s，保存

3. 在新的页面最前面输入我们新的commit message

遇到一个不懂的问题，希望老师解答一下。
首先是git rebase -i commitid 执行之后，把窗口关了，再次进来使用git是下面这个情况
su@sun-PC MINGW64 /e/learninggit/git_learning (master|REBASE-i 1/2)
然后使用git rebase --abort命令，报错如下
su@sun-PC MINGW64 /e/learninggit/git_learning (|REBASE-m)
$ git rebase --abort
error: could not read '.git/rebase-merge/head-name': No such file or directory
这种情况下还需要怎么改呢，还能恢复吗

请问下老师，
我在执行完git rebase指令后，出现下面提示的错误，按照提示执行git rebase --continue 之后，可以成功合并4个commit。但不太理解为什么会出这个错误？以及错误提示中提到的git rebase --continue 和git rebase --edit-todo是什么意思。

谢谢

coexs-MBP:git_learning coex$ git rebase -i 80766daa0ba0a150a
[detached HEAD 46caa3d] Create a complete web page adding index and logo Adding style Adding js
 Date: Wed Dec 19 22:00:31 2018 -0800
 4 files changed, 132 insertions(+)
 create mode 100755 images/git-logo.png
 create mode 100755 index.html
 create mode 100755 js/script.js
 create mode 100755 styles/style.css
error: Your local changes to the following files would be overwritten by merge:
    readme
Please commit your changes or stash them before you merge.
Aborting
hint: Could not execute the todo command
hint:
hint: pick 800f537f1c5a760c779af586ed3534dc9cfbfaaf Moving filename readme to readme.md
hint:
hint: It has been rescheduled; To edit the command before continuing, please
hint: edit the todo list first:
hint:
hint: git rebase --edit-todo
hint: git rebase --continue
Could not apply 800f537... Moving filename readme to readme.md
coexs-MBP:git_learning coex$ git rebase --continue
Successfully rebased and updated refs/heads/master.

老师，合并出现的问题如下：
Administrator@PC-DriveMan MINGW64 ~/git/learning (master|REBASE-i)
$ git rebase -i 2fb364994b6
fatal: It seems that there is already a rebase-merge directory, and
I wonder if you are in the middle of another rebase. If that is the
case, please try
        git rebase (--continue | --abort | --skip)
If that is not the case, please
        rm -fr ".git/rebase-merge"
and run me again. I am stopping in case you still have something
valuable there.


Administrator@PC-DriveMan MINGW64 ~/git/learning (master|REBASE-i)
$ git rebase --skip
Auto-merging index.html
CONFLICT (add/add): Merge conflict in index.html
error: could not apply b030c3a... Add index.html
Resolve all conflicts manually, mark them as resolved with
"git add/rm <conflicted_files>", then run "git rebase --continue".
You can instead skip this commit: run "git rebase --skip".
To abort and get back to the state before "git rebase", run "git rebase --abort".
Could not apply b030c3a... Add index.html

Administrator@PC-DriveMan MINGW64 ~/git/learning (master|REBASE-i 1/6)
$ gitk
git rebase --continue

sdaf
git rebase -i
git rebase -i 2fb364994b6d9820

后面我不管输入什么 好像都没有效果，不知怎么解决

请问下老师，合并连续的commit message出现的问题如下，是什么原因呢？
You asked to amend the most recent commit, but doing so would make
it empty. You can repeat your command with --allow-empty, or you can
remove the commit entirely with "git reset HEAD^".
interactive rebase in progress; onto 15b6f27
Last commands done (4 commands done):
   squash db93f64 修改Readme名称
   squash f15cbd4 modific readme name
No commands remaining.
You are currently rebasing branch 'master' on '15b6f27'.

No changes
Could not apply f15cbd4... modific readme name