The search creator filter using views ajax request allows us to add some user content type from the settings. However, the API doesn't allow multiple content type identifier values when it comes to ContentTypeService->loadContentTypeByIdentifier($identifier, array $prioritizedLanguages = [])

Step to reproduce:
1. Create new user2 contentType and add ezuser fieldtype and two ezstring fields for first and lastname
2.Create user "John Doe" using user2 ContentType
1. Add following to parameters.yml

ezsettings.default.user_content_type_identifier: ['user','user2']

2. Clear cache
3. Go to Backend->Search
4. Open the filter and try to search for "John"

Expected:

• User John is shown in the Creator drop down list

Current Issue

• 404 error in the browser console:

  Type with identifier ID: user,user2 Not Found

  (see screenshot for better explanation)