Reports are not visible to some users

[Madhan007]

Hi Everyone,
We have a Dashboard with some List type reports on Idea(idea) table. The records in the reports are grouped by business_unit.description field.(Business unit is a field in idea table referencing business_unit table). Reports and Dashboards are shared to the user. I checked read, report_view,query_range ACLs, Query Business rules on both idea and business_unit tables and user satisfy all the conditions, still the report is throwing this error

Note : User is accessing the report in Native UI and not in workspace and user was able to access those reports untill a day ago and we have not made any changes to the reports or the tables.

Any Insights into this is highly appreciated. Thanks in Advance!

[SVimes]

If you can, turn on the ACL debugger (Debug All Security) then impersonate the user. The ACL debugger should continue to run while you are impersonated and allow you to see more clearly which ACL(s) might be causing the problem.