The answers are in the details.
What version of Premiere Elements and on what computer operating system?
Because of the nature of your thread title, I am guessing that you have Premiere Elements 13/13.1. For now I will assume on Windows 7,8, or 8.1 64 bit.
This error is a known one for Premiere Elements 13/13.1. The Adobe solution is to delete or disable the OldFilm.AEX file.
This file is found
Local Disk C
Adobe Premiere Elements 13
and inthe NewBlue Folder is the OldFilm.AEX file that you delete or disable by renaming to OldFilm.AEXOLD.
Please let us know if that worked for you. If not, more information, please.