The Microsoft with Feedback machine translation service does not support batch pre-translation (e.g. to translate the entire file at once via the Pre-translate menu in Memsource Cloud). It can only be used for segment-per-segment pre-translation in Memsource Editors.
If you need to run batch pre-translation, please use one of the other MT services available.
Please note that batch pre-translation is not really recommended for Memsource users. You will find more details here.