You probably should use the Better Search and Replace plugin.
But before using Better Search and Replace you can use our diagnostic pages to see the condition of your file paths. Just activate the Media Library Plus Reset plugin and the click on Media Library Plus Reset-> Display Attachment URLs and Media Library Plus Reset->Display folder data.
When running Better Search and Replace please backup your database first. Then when you run it check the option to update ‘guid’ fields and uncheck the dry run option.
After running Better Search and Replace, deactivate Media Library Plus, activate Media Library Plus Reset and run Reset Database (this does not change any files on your servers or attachments records in the database. It only removes data added and used by Media Library Plus). Then reactivate Media Library Plus and go to the Media Library Plus page. Your media library will be rescanned and it should display the page with no problems