Looks like it is part of the TestStand installation.
I have never been a fan of using these. To me it seems to be bad practice to read and write variables from TestStand from within LabVIEW.
I have legacy code that uses them. I was having no end to issues with runtime engine conflicts in deployments. I was able to resolve this issue by deleting the directory, force reinstalling TestStand, and then mass compiling the TS addons directory in LabVIEW.