Tip: submit form via InfoPath client when InfoPath Forms Server submit reports a problem

Context:

Upon submit of a form via InfoPath Forms Server, encounter the InfoPath error "An error occurred while the form was being submitted". That's it, no more error details displayed, nor to be found within the logging.

Problem analysis

So, how to detect what is the concrete problem cause? Tip: try to submit the same form directly via the InfoPath designer client. If the problem also occurs within this host context, you can here view more error details. In my situation, the error details displayed "A value in the form may be used to specify the file name. If you know the value in the form that specifies the file name, revise it and try again. Otherwise, contact the author of the form template". Translation, I forgot to specify a filename pattern within the submit options to make it unique.