Try This First

Before you open a new support ticket check out the following solutions.
Maybe we have already covered your issue here:

1. Can not log in to staging site
2. Page not found, error 404 after pushing
3. Staging site returns a blank white page
4. Activate permalinks on staging site
5. Server Error 500 trying to access the staging site
6. Staging site redirects back to live site
7. Can not update WordPress on staging site