When creating reports in p6 v7, some users can create and run a report with 0 projects open which executes the report on all projects. Some users cannot do this as the report comes out blank. is there a preference somewhere ?
This would depend on what kind of privileges are assigned to each user. Go to Admin > Users. Users that are not Admin Superuser or Administrator may not be able to run reports. Also, go to Admin > Security Profiles. You can check to see if the user has the privilege to Edit Global Reports or Edit Project Reports under Global Profiles or Project Profiles.