All Pharos-supplied modules produce a file called results.txt, which contains information about the success or failure of the module's install. Custom modules can produce a results.txt file as well. However, if this error occurs the custom module does not create this file.
To stop this error and allow the package to install successfully open Pharos Administrator and go to:
Distribution System->Packages->Custom Modules->Select the module->Module Behavior (on properties tab) and check “Module does not write results.txt file”