jordanjay29 Wanted to install Flarum( Ubuntu+Nginx) and I have the same issue. Glad I found this post to not duplicate it here.
Unfortunatelly I did all the above, I guess, and the error message is still prompting on the install page. Both asset and storage folders have: Access: (0775/drwxrwxr-x) Uid: ( 33/www-data) Gid: ( 33/www-data)
Any help would be much appreciated.