Yes, logically the pkg/MetaRepository is page only accessible, when the MetaRepository package is installed and enabled on Your NAS.
I mean check some log file or install something?!
May I need to reset back to factory default settings?
Nope and no.
Did You copied the web_prefix file to the admin/zy-pkgs share? Is the file contains this?:
If all Your answers for the past questions are yes, make sure, the web_prefix file hasn't got any extension. Because if it has an extension, like .txt, the NAS Cannot handle it. So if You created the file using Windows, You Can remove the .txt with Total Comander's renaming function, or You Can use the cmd and the move command to do that.
Thanks nas-central the lot of help!