Daily get_config_string failed: PRODUCT_DATA_D: Unexpected end of data errors

[webaus]

We have an 8.6.0.4 install in windows 2008 that almost daily gets the error:

get_config_string failed: PRODUCT_DATA_D: Unexpected end of data when read C-string from serializer.

any ideas what is causing this?

identical installs don't suffer the same issue