Solution Fatal error: Uncaught Error: Call to undefined method SubmissionFileDAO::getAllFileStages OJS 3.3.0.8 after upgrade to thar version of OJS.

Thank you for asking, all my plugins are updated…
Fatal error: Uncaught Error: Call to undefined method SubmissionFileDAO::getAllFileStages() in /www/htdocs/journal/controllers/wizard/fileUpload/FileUploadWizardHandler.inc.php:35 Stack trace: 
#0 /www/htdocs/journal/lib/pkp/classes/core/PKPRouter.inc.php(387): FileUploadWizardHandler->authorize(Object(Request), Array, Array) 
#1 /www/htdocs/journal/lib/pkp/classes/core/PKPComponentRouter.inc.php(257): PKPRouter->_authorizeInitializeAndCallRequest(Array, Object(Request), Array) 
#2 /www/htdocs/journal/lib/pkp/classes/core/Dispatcher.inc.php(144): PKPComponentRouter->route(Object(Request)) 
#3 /www/htdocs/journal/lib/pkp/classes/core/PKPApplication.inc.php(362): Dispatcher->dispatch(Object(Request)) 
#4 /www/htdocs/journal/index.php(68): PKPApplication->execute() 
#5 {main} thrown in /www/htdocs/journal/controllers/wizard/fileUpload/FileUploadWizardHandler.inc.php on line 35

In our case: This issue was coming because the previous version of OJS was copied in conflict with the new version – Backup the old code 3.1.1 (to not merge both version)
Start with a fresh version of OJS 3.3.0.8, use the update option