Filesync 7.6 wiped all my files

[m4ster2k]

After installing version 7.6, run the application to mirror all the users folder. However, during the process he gave a crash and the application wiped all my files in this folder without making a copy. I lost all my files. I tried to recover the files with three different programs without success. what to do?

[Zenju]

When an application crashes it cannot delete any files, the process is essentially dead, doing nothing anymore. In the case of FreeFileSync there is no point in time where a crash could lead to data loss since files are overwritten only after the replacement files was copied correctly (the feature is called "fail-safe file copy", enabled by default).
However what FreeFileSync cannot entirely prevent are incorrect configurations, like confusing source and target directories (however even in those cases it will show a warning about a "significant difference" of the data sets).
In these situations the options for data recovery depend on the file deletion settings:
https://freefilesync.org/faq.php#restore-files