Now this might not fix your issue but Version 9.6.1 is rather old and has some security vulnerabilities. So I would upgrade to one of the LTS/MTS releases (latest currently 9.12.5).
And if you search on the term in the forum you would see some other probable causes for this error that also might fix it:
This issue is occurs by administrator user role is not selected correctly in the project security of application.
And also if security is turned off, while the administrator user role is not selected or no longer exists. So set security to either demo/production, and select a user role on the administrator tab.
Hi @Yiting Li, did you get any solution for this issue ? I'm also facing the same issue with 9.12.10. and also with other cub version of 9.12. Please let me know if you were able find any solution.