I've seen this error on a couple domain controllers running IIS apps. It doesn't seem to have an associated symptom for end users, but I suspect it requires some extra authentication on their part when running more secure web apps.
Error: The Template Persistent Cache initialization failed for Application Pool 'DefaultAppPool' because of the following error: Could not create a Disk Cache Sub-directory for the Application Pool. The data may have additional error codes..
See MS Knowledgebase article KB ID=332097. It describes manually setting security on various IIS related folders.