after 3 days with no issues with ON, last night a completed survey ended with:

Hmm, there seems to be a problem…
Please review the error message below and correct it. If you are unable to resolve
the problem, go ahead and contact us for support and we will gladly help you.
Fatal error when executing user-defined code
Sorry, due to an error this survey is currently unavailable.
We apologize for the inconvenience and suggest that you re-take this survey later.
The administrator has been notified about the error and will take action immediately. If you contact support about this error, please reference the code "XFCWC""

I noticed there is now a survey number which I included in my e-mail to ON. interested to see what happens with this