When I try to export to mpg2 140 x 1080i 30 an error message comes up and export cancels.
When I click the render box on the timeline, the CTI goes to the same brief clip and plays it, then stops. No rendering takes place, and the clip remains selected.
Also I don't find an export option for mpg4.
What version of Premiere Elements and on what computer operating system is it running?
For now I will assume, Premiere Elements 11, 12/12.1, or 13/13.1 on Windows 7, 8, or 8.1 64 bit.
Do you have the latest version of QuickTime installed on your computer along with Premiere Elements? If not, please do so. That may be the answer to the MPEG2 issues and a lot more.
As for export of your Timeline content to file saved to computer hard drive with .mp4 file extension, please look for your opportunities
Presets.......one of the MP4 presets which can be customized under the preset's Advanced Button/Video Tab, Audio Tab, and, if applicable, Multiplexer Tab.
Mobile Phones and Players
Apple iPod, iPad, iPhone
and one of the .mp4 presets there.
Please review and consider, and supply more details so that we can fine tune the information.