RushFiles Work by detecting changes on files, so using a database system like MS access or similar, that is not a database server system, but a local file getting changed all the time, is not a good idea.
Most of them are not designed to be use on a share system where the file can be accessed from multiple users and online/offline at the same time.
This will result in conflicts and corupted databases. As these programs write directly into the files and dont respect the normal update / create of the file operation system.
In short, Dont use Access and other filebased databases on sync-and-share systems.
Use the database on a local Drive (like C:), and copy the file to the RushFiles folder, after it's updated and the database program is closed.
A more advanced version is to setup a scheduled copy of the file.