NAS326 unable copy/move/delete folder or file after last firmware update

Ok, so there seems to be an issue with the Zyxel NAS326, I have just purchased one in May 2019 & had the same issues. Not sure about updating firmware as there seems to be lots of negative comments about it, however I have managed to delete files on my NAS326 using the following method.

1. Install Filezilla on the PC you access your NAS326 with.
2. On your NAS326 create a new user with administrator read/write privileges.
3. Run Filezilla & logon to your NAS326 using it's IP address 192.168.... etc. etc. (whichever yours is) in the Filezilla host box, the username for the account you just setup along with the password in Filezillas username & password boxes, & 21 in Filezillas port box, then click Quick Connect.

Filezilla should connect to your NAS326 & bring up the Photo, Music & Video folders in the right hand 'Remote Site' Pane. Double Click into whichever folder you want to delete files from, right click on the file & select delete.

Using FileZilla you could also upload/manage files much quicker than using the NAS326 interface.

Hope this helps.

Hey guys,
Looks like I have a solution:
1) I downgraded firmware to V5.21(AAZF.1) - it still wants to update it, but I don't care
2) I have no access to upload / delete files across Windows "network locations"
3) I tried "Connect the network drive" and  "Connect with other credentials" - using the same username and password as I have in my NAS.
And it works. 
I hope it will help you...
PS: I have Windows 10 and everything is translated from Czech, I don't know the original names of commands ...