HTTP Error 500 (Internal Server Error) bulk uploading with a page creator plugin

I am using a bulk page creator with the intent on making a page for every city in usa. i have 30,000 and it appears that the page creator only is successful with about 2800 at a time. so i am chunking off the data in that amount and was going to do this 12 times on the third time it froze up the page tab in my wordpress admin. it came up with this error.
The website encountered an error while retrieving

It may be down for maintenance or configured incorrectly.
Here are some suggestions:
Reload this webpage later.
HTTP Error 500 (Internal Server Error): An unexpected condition was encountered while the server was attempting to fulfill the request.

I checked with the host and we did hit some data memory limits and increased those but i have plenty of space and they conclude that it is a wordpress issue. i have updated my version of wordpress and it has 5800 pages on my server i was after updating the first 3000 just uploading them one after another into the drafts folder. is there a page limit, is there a drafts page limit. i was on the third upload and there are 3000 pages active and 5000 in drafts and my server says i have 5800 pages the next upload that blew up was going to get the total to about 12,000. what is the issue and how do i fix it.