Add more checks for edgecases (e.g. when user_field is removed)

lib/custom_wizard/builder.rb

@@ -258,7 +258,9 @@ class CustomWizard::Builder
         }
       ).perform
             
-      if content.present?          
+      if content.present? &&
+         content[:result].present?
+         
         if content[:type] == 'association'
           content[:result] = content[:result].map do |item|
             { 

lib/custom_wizard/mapper.rb

@@ -188,7 +188,7 @@ class CustomWizard::Mapper
   
   def map_user_field_options(value)
     if value.include?(User::USER_FIELD_PREFIX)
-      if field = UserField.find(value.split('_').last)
+      if field = UserField.find_by(id: value.split('_').last)
         field.user_field_options.map(&:value)
       end
     end