Change

app/controllers/application_controller.rb

@@ -750,7 +750,7 @@ class ApplicationController < ActionController::Base
 			@project
     elsif current_user.is_a?(AnonymousUser)
 			logger.info "###########：This is AnonymousUser"
-			@project = nil if !@project.is_public
+			@project = nil if @project && !@project.is_public?
 			render_forbidden and return
     else
 			logger.info "###########：project not found"

app/controllers/projects_controller.rb

@@ -116,7 +116,7 @@ class ProjectsController < ApplicationController
   end
 
   def project_public?
-    return if @project.is_public
+    return if @project.is_public?
 
     if current_user
       return if current_user.admin? || @project.member?(current_user.id)

app/models/project.rb

@@ -122,7 +122,7 @@ class Project < ApplicationRecord
 
 
   def can_visited?
-    is_public || User.current.admin? || member?(User.current)
+    is_public? || User.current.admin? || member?(User.current)
   end
 
   def releases_size(current_user_id, type)

app/views/users/projects/shared/_project.json.jbuilder

@@ -5,8 +5,8 @@ json.members_count project.members.count
 json.issues_count project.issues.count
 json.changesets_count project.project_score&.changeset_num.to_i
 
-json.is_public project&.is_public
-json.can_visited project&.can_visited?
+json.is_public project.is_public?
+json.can_visited project.can_visited?
 
 json.owner do
   json.partial! 'users/shared/real_user', user: project.owner

app/views/users/subjects/shared/_subject.json.jbuilder

@@ -5,4 +5,4 @@ json.image_url url_to_avatar(subject)
 json.owner_id subject.user.id
 json.owner_name subject.user.full_name
 json.visits_count subject.visits
-json.can_visited subject&.can_visited?
+json.can_visited subject.can_visited?