"Function not available to this responsibi​lity" Error While Clicking On Forms Personalis​ation

To resolve the issue:
1. Log in as the System Administrator
2. Navigate -> Profile -> System -> User
3. Select an appropriate level (i.e. Site, Application, Responsibility, User)
4. Query the following profile: Utilities: Diagnostics
5. Set option to Yes and commit
6. You must log off and log on again for the settings to take effect.
Then retest for your issue.

Ref - Metalink Note - 1263970.1