The software didn't change between when it worked and when it doesn't. More likely might be that something in your computer changed. It is not impossible that one of the many Premiere Elements program files was corrupted by a disk error. If it were me, I would try an un-install through the operating system, followed by an install with a fresh installation file downloaded from Adobe.
You need to provide details for anyone to help Mac or Windows and exact version of the operating system CPU brand and model and clock speed Video adapter brand and model and driver version and amount of video ram Number and size and type of hard drives