Try connecting your iPad to a desktop computer via iTunes and manually pull your file out. Here is a link from Apple.
If you can't open the file, there is not a way to export it. If you were not using iCloud support, it won't be backed up. This would leave you with that one method of retrieving the file.
If you were using iCloud Support, see if you can set up iCloud Drive on a desktop and retrieve the file from there. If you get the file, feel free to submit a support ticket with it, and PreSonus would be happy to assist.