Your software 
Your problem 
Migration 20230522115137 failed during Execution. Error Undefined constant MauticPlugin\MauticCitrixBundle\Integration\CitrixAbstractIntegration::DEPRECATION_MESSAGE
In Version20230522115137.php line 38:
                                                                                                                 
  Undefined constant MauticPlugin\MauticCitrixBundle\Integration\CitrixAbstractIntegration::DEPRECATION_MESSAGE  
Steps I have tried to fix the problem:
Cleared cache 
Validated issue exists on multiple boxes 
 
             
            
              
            
           
          
            
            
              After a quick look i think there is an issue in the migration file, there is no constant declared in the bundle class and yet the migration is referring to it.
Further more all this migration does is insert some warning that I guess is telling you that citrix is deprecated. If you deactivate the plugin and try to run the migration again it should be ok.
You can also “fix” the issue by changing the line here:
  
  
    
    
      
          
                   if (!$pluginInUse) { 
                      throw new SkipMigration('The Citrix plugin is not used on this instance, no need to add deprecation notifications'); 
                  } 
              } 
          
               public function up(Schema $schema): void 
              { 
                  $table   = "{$this->prefix}notifications"; 
                  $header  = 'The Citrix plugin will be removed in Mautic 5.0.0'; 
                  $message = CitrixAbstractIntegration::DEPRECATION_MESSAGE; 
                  $sql     = "INSERT INTO {$table} (user_id, type, header, message, date_added, icon_class, is_read) SELECT u.id ,'warning', '{$header}', '{$message}', NOW(), 'fa-warning', 0 FROM {$this->prefix}users u"; 
                  $this->addSql($sql); 
              } 
          } 
       
     
  
    
    
  
  
 
to something like this:
$message = "Citrix is not available on Mautic 5";
Hope this helps.
Regards, M.
             
            
              
            
           
          
            
            
              @steverobinson  would you mind raising it as a bug on GitHub?
I think it’s hopefully a quick fix which we can push out in the next patch release.
             
            
              
            
           
          
            
            
              Thanks! I ended up skipping (deleting) the migration for now since we’re not running the plugin at this time, but your fix is a lot more elegant!