Please go to console, your error will be logged there. Double click, you will get the reason for error.
Can You please check is there access have been given to the respective pages for the User roles.
As Rishi says, if you look in the console in Mendix Studio Pro you should be able to find the error. It should be in red so easy to find. If you double click it you will get a more detailed error message. If you are still stuck after looking at this message, please post it up to the forum where someone should be able to help more.