What version of Premiere Elements, what computer operating system?
What are the properties of what was on the project's Timeline when hitting Save froze the project? What are the readings for Editing Mode, Timebase, Frame Size, and Pixel Aspect Ratio (even if they look grayed out) found under Edit Menu/Project Settings/General?
What will not open - this particular project, the whole program, and new projects?
What was the size of the project when you tried to save it and everything froze?
Have you created, saved, reopened other projects successfully before this happening?
What are your computer resource detail - processor, clock speed, installed/available RAM and free hard drive space?
The answers will be in the details. Please consider and supply the all details.
Any questions or need clarification on the above, please do not hesitate to ask.