Part X of what form?
You may need to fill out that section manually and mail the form.
efiling is required for that amount of assets (I think the threshold is around $25 million)
ProSeries does not allow for dollar amounts greater than $1 billion in Form 990.
That would have been nice to know before I purchased the software.
Solution is to upgrade to Lacerte.
If I remember correctly, if you purchased ProSeries they let you use Lacerte on a Pay-Per-Return basis.