How can I recover a broken Git workspace?

My configuration is with Win10, latest Git 2.10 and I work with GitHUB using SourceTree. For SourceTree, it uses the Git version of my system (not the embedded one).

Apparently a couple of files of 2Mb size (yes I double checked it), pop-up a warning inside sourceTree when trying to stage the files, asking for lfs connection and configuration. I followed up the lfs set up (from within sourceTree). At this point, trying to get the git status reports this error.

git-lfs clean -- 'path/AMyimageI.png': git-lfs: command not found

error: external filter git-lfs clean -- %f failed -1

error: external filter git-lfs clean -- %f failed
fatal: path/AMyimageI.png: clean filter 'lfs' failed

Which then took me to install the git lfs from here, followed by the "git lfs install". Another try to "git status" (from pure Git bash) only hangs and does nothing.

After uninstalling git-lfs and restarting SourceTree I get this warning

and again the previous error is reported.

Some of my files are staged already, some not. I don't want to reset to my last commit and get my work lost. What are the possible solutions to recover git from this error?

I tried just letting my partial commit go, from the Git bash, again no response.

Appreciate your help.

Cheers.

Clicking the NO, in the SourceTree pop up window fixed the problem. Apparently a conflict happens locally installing the git lfs and the one that's been used in our GitHUB.

I did have to uninstall git lfs also and all works. Thank you.