If your users are unable to view data in Salesforce, this could either be due to page layouts OR permissions.
Here are the steps to troubleshoot:
- Login to your Salesforce org and click on Manage Users under the Administer column on the left hand side of the screen --> Select Users --> Click on the user.
- In the Permission Set Assignments related list, click Edit Assignments.
- To assign a permission set, select it under Available Permission Sets and click Add. To remove a permission set assignment, select it under Enabled Permission Sets and click Remove.
- Click Save.
Please note that you can choose, if permissions are not assigned, to either do it at the User or the Profile level. If you update at the profile level ALL users with that profile will have the permissions. If you update at the individual level then only that single person will gain permissions.