Can't use backup process.

Hey everyone,

I have a weird problem and i hope that someone will be able to help me on this.

I'm not understanding verything clearly about networking in general but, in the past, i managed to make my ReadyNas work and backup two directories on my computer to the NAS.

Now, it's not working anymore on my Windows 8.1 (it didn't work on my previous Windows 10 system either).

What i did :

-i created a user called NAS on my computer and granted him full acess to the directory that i want to backup.

-I created a backup job and use this user to connect to my computer.

-i setup all the informations including the directory where i want to store the files on the nas

- then i used the "Test connection" button and it says that everything is ok (great !)

But everytime i try to launch the backup, no matter what i experiment, i always have that message : "Source cannot be mounted on the system ", and i realy have no idea what to do to resolve this. I mean, i'm not good with networdking stuffs but i think the way i did was good, was it ?

Does someone has a solution for me ? Or maybe could tell me what i'm doing wrong ?

Thanks for reading this and have a nice day.