Unable to delete ffs_tmp files

[ntj]

I received the below error message on 2 ffs_tmp files in my right folder. I
have mirroring set up.

Windows Error Code 32: プロセスはファイルにアクセスできません。別のプロセスが使用中です

It says that it can't access the file because another process is using the
file.

Anyone have any ideas on how to fix this?

Thank you

[Zenju]

Are you using the most recent version of FreeFileSync? The error message
should say which application is locking the file (if possible)