Points to check
1. Login into Central Management Console(CMC) with Administrator credentials.
2. Navigate to Users & Groups -> Select Group List -> Right click on the group the user is member off->Customization->Features->Check if the Design Mode Feature Enabled or disabled.
3. Navigate to Folder-> Navigate to the report path -> right click on the report->check user security for view permissions.
p 4. Open the report->On the File tab, Click the Save drop-down menu
b. Click Save as
c. Check the checkbox “ Remove Document Security “
d. Click Save
e. If you are saving in same location as in original file, Pop-up asks if you want to overwrite the file, click Yes
5. Log out completely from BI launch pad or Rich client. And re-login to test