Remote access can be tricky depending on your home network setup, router configuration and ISP. However if you cannot even access the Plex forum / web app, this means there might be something else going on with the network configuration of those clients (laptop, mobile phone).
As for the client network access… are those devices connecting to the network through some VPN or other security apps/tools/components? Any special DNS configuration on those devices?
I was referring to the configuration of the laptop / mobile phone as those cannot access the server from outside your home network (or even the Plex forum).
Can those devices access your server from inside your home network?
If the change / issue is related to upgrading to DSM 7… have you enabled any special network configuration on the Syno (e.g. Synology’s DDNS, some NAS specific firewall configuration…)?
best verify that… DSM7 has some significant changes.
Not sure what Youtube video you found – just as reference for anybody finding this thread… here’s a link to the verified guide on how to handle the DSM6->7 migration with a Plex Media Server.
To my knowledge yes I had DSM 6.0 when I installed my plex app via snyology apps store
I then kept getting bothered by synology to upgrade to DSM 7 and when I did my plex apps on my tv’s and mobile said "server not available "
So I went on you tube and watched the video on how to re organise your library to make DSM 7.0 work with plex beta.
Since then I have had many issues with networking and audio problems with the LG tv for example.