Slim Application Error

[wachirawamwangi]

I am having issues running nextcloud on my digitalocean droplet and I get this error.

I have seen similar issues raised here but the only comments there advise posters to create a new issues.
OS is Ubuntu 20.04
I have several other services running meaning ports 80, 8080 and 443 are already occupied.
I have a domain with two subdomains, with one of the subdomains - with ssl - already running in the same droplet.
I am however able to access the setup page but once I enter the password in the login page it brings this error.
I am new to everything docker, reverse proxy etc etc
Thank you in advance for your assistance

[Cedrik12]

I have the same problem in this discussion : #2898

[szaimen]

Hi, it looks like port 443 is already used on your server. Please follow https://github.com/nextcloud/all-in-one/blob/main/reverse-proxy.md thus.