Author Role (Preview change-button) NOt working

hello hopefully some here an help …

when author tries to see edit -changes by clicking on (Preview Changes-button) on his/her post . It redirects to https://site.com/wp-admin/post.php
Instead of redirecting to the actual post type
https://site.com/wp-admin/quiz/post-name/ this gives a blank page.

Now if you select same button (Preview changes) and righ click – open new tab- it shows the actual post like: https://site.com/wp-admin/quiz/post-name/ ..

a.Can some one tell me how to — make this button properly work on author role by just direck cliking on it ?

b. does any one nows were are author roles settings found ? and the file location of this author role function ?

things i have tried:
1. disable all plugins- multisite and subsite
2. check with different themes
3. downgraded wp == from 4.2.2 to 4.1.5 nothing