How to solve 500 error after deploy using capistrano?

Question

PHP

There is a site on php (yii). I post to the server using capistrano.
The process runs without errors, the site is copied without problems. When switching, an error 500 is issued.
I saw a solution on the Internet with changing the rights to folders for the -w group, but this did not help (the folders did not have write permission, and so).
Maybe someone already solved a similar problem?
deploy.rb

lock '3.4.0'

set :application, 'site.ru'

set :scm, :git
set :repo_url, '[email protected]:gogolinsky/site.git'

set :deploy_to, -> { "/home/user34/domains/#{fetch(:application)}" }
set :current_dir, 'public_html'

set :group_writable,  false

set :tmp_dir, "/home/user34/temp"

set :default_env, {
   :LANG => 'en_US.UTF-8'
}

set :keep_releases, 4

Answer 1

I think almost everyone solved problems with a 500 error. Only there can be a million such errors.
Read the logs.