It would be great if the error being thrown in the JIRA UI will be more specific rather than giving a generic error message. Perhaps, giving hints on why something is not working. 

As an example, on the issue navigators's advanced search,

"A value with ID 'xxxxx' does not exist for the field 'project'."

In this case, user running the JQL doesn't have a permission on the project. It would be better if the error will be something like:

"A value with ID 'xxxxx' does not exist for the field 'project' or user has no access to the project.".