Support intro
Sorry to hear you’re facing problems 
help.nextcloud.com is for home users. If you’re running a business, get help on portal.nextcloud.com so we can make sure your business keeps running smoothly.
In order to help you as quickly as possible, before clicking Create Topic please provide as much of the below as you can. Feel free to use a pastebin service for logs, otherwise either indent short log examples with four spaces:
example
Or for longer, use three backticks above and below the code snippet:
longer
example
here
Remember, the below information may be requested if it isn’t supplied; for fastest response please provide as much as you can 
Please delete everything above when creating your topic and provide the following:
Nextcloud version (eg, 12.0.1): 13.0.1
Operating system and version (eg, Ubuntu 17.04): 16.04.2LTS
Apache or nginx version (eg, Apache 2.4.25): nginx 1.10.3
PHP version (eg, 7.1): 7.0
The issue you are facing: can’t include external paths into user data directory.
Is this the first time you’ve seen this error? (Y/N): N/A
Steps to replicate it:
- cd /var/www/mydomain.com/nextcloud/data/uaserA
- ln -s /anylocation/shared_directory/ shared_directory
Hello as mentioned up, I just come with a fresh install of Nextcloud 13.
My consern is about how to ass a share (symbolic link) into the data/userA directory, and make it visible into the UI.
I can’t use the work around to copy data via the UI, cause it is TB of data, it would be too large/long.
I did try to use occ to clean up the cache , and reread the directory , that won’t change anything.
Note : userA have the proper rights to read/write the external data.
Thanks a lot for your help.
and update here.