by Michael Hughes.
We're seeing this as well:
There was a problem sending your submission to Turnitin: Coding error detected, it must be fixed by a programmer: Could not load preference popup_provider_mod_turnitintooltwo_submission_permitted. Make sure the component and name you supplied to message_send() are valid.
However in our case we have the mod_turnitintooltwo module disabled as we only use the Plagiarism plugin...
We followed the instructions, but had to enable the activity module to get the settings to be listed and hence pick up a value.