Hi,
On the files availables on my nextcloud instance, when I click on the Share button I’ve got no more option for sharing file.
My configuration :
at least i think you need to setup your emailserver within nc.
I am having the exact same issue, can’t share files, can’t view file sharing activity, all menus regarding file sharing are gone.
Disabling all plugins does not resolve the issue.
I am running 18.0.6 stable with php 7.3.
I want to emphasize that the mailserver options are configured and I can send emails using nextckoud.
did you receive any testemail when you configured your serviceemails?
like under adminaccount - Settings - Administration - Basic settings ?
Yes, of course otherwise I would not have stated that I can send emails using nextlcoud. I just send another test mail to reverify that I indeed do receive mails from my nextcloud instance.
i just wanted to make clear that we were talking about the same thing… 
how have you hosted your instance?
My instance is hosted on a dedicated machine in a data centre in the Netherlands. Nextcloud is manually installed using apache, mariadb and php.
Checking the logs indicate no errors around sharing acitvities. There are no warning, error or fatal messages in my entire log.
The javascript console shows no errors when pressing the share icon on a file or pressing enable sharing under chat.
when did that happen? and how?
That is exactly what I would you to figure out, all things indicate this must be a bug. I do not have any clear idea as to how and when this exactly happened.
To clarify, the buttons are still there but pressing them does nothing and the menus never show.
would you mind sending me credentials for a testaccount (no admin!) for your instance in a private message?
Sure, how do you send private messsages though?
click on reply…
a new window opens at the bottom of the screen.
in the upper right corner of this new window you see a small right-arrow followed by my icon and nickname.
click on the arrow… chose email 
It says, sorry you can not send a personal message to that user…
wow. maybe becaue you are too new, still?
ok. wait. i try sending you a PM and maybe you could reply to it…
Disabling uBlock in Firefox resolved the issue for me, Seems there is currently a rule that is to aggressive.
Disabling uBlock on the site worked for me too in 2020. Guess ‘sharing’ as a word has been hijacked by aggresive social media pushers 
