修复

app/queries/blockchain/balance_query.rb

@@ -14,6 +14,7 @@ class Blockchain::BalanceQuery < ApplicationQuery
       token_list.each do |t|
         project = Project.find_by(id: t['token_name'].to_i)
         if project.nil?
+          result_list << {project: nil, balance: t['balance']}
           next
         end
         owner = User.find_by(id: project.user_id)

app/views/users/blockchain_balance.json.jbuilder

@@ -1,5 +1,7 @@
 json.total_count @total_count
 json.projects @projects.each do |p|
-  json.partial! 'projects/detail', locals: { project: p[:project] } 
+  if p[:project].present?
+    json.partial! 'projects/detail', locals: { project: p[:project] } 
+  end
   json.balance p[:balance]
 end