ChangeAuditor Agents will not install on computers that have ScriptLogic's Active Administrator software installed on them.
This issue is already mentioned in the ChangeAuditor release notes.
The reason for this is a software incompatibility due to the nature in which both products work.
Either ChangeAuditor or ScriptLogic's Active Administrator can be installed but not both. To have ChangeAuditor Agents correctly auditing these machines, one would have to first uninstall ScriptLogic's Active Administrator software from these machines.
From the ChangeAuditor versions 5.0, 5.1 and 5.5 release notes:
Software Incompatibilities Agent installation is blocked if the following applications are found:
Pre-4.8 versions of ChangeAuditor
Older versions of InTrust plug-ins:
ITAD: Pre-3.2 versions
ITADAM: Pre-3.2 versions
ITFA: Pre-2.0 version
ITEX: Pre-2.0 version
ScriptLogic Active Administrator