Linked files can't be opened after moving the bak file

I’m quite new to JabRef and I thought Bak file and File can be moved. But after moving them, I can’t open my file links. Someone please help me

The .bib file and the .bak file can be moved around, but the directory to the file links have to be defined accordingly.
In the menu File -> Database properties, set the General file directory using a relative path, such as ./MyFiles (or .\MyFiles depending of your operating system).

Afterward, you should be able to move your database and your files around.

More details here:

Does that mean if I didn’t define before moving, I won’t be able to open my links? Cause I defined and the links still can’t be opened. Do I have to reattach all those files?

Try to set the file directory to the folder where the bib file was previously.

Thanks a lot! It worked this time. Omg thank you

Also, another question. I noticed that another Bak file will be created every time I saved the database. Is it safe to delete the previous Bak files and keep the latest saved Bak file?