What version of Premiere Elements are you using and on what computer operating system is it running?
Please explain "...today...it installed an upgrade..." What upgrade?
Are you a home user of the program or part of a school or company network?
Let us start with the above and then decide what next.
I am using version 13.0 (20140903.daily.717136)
I am running Windows 7 Pro
I am a home user
I did some homework on your question while the Adobe Premiere Elements Forum was down for updating last night.
It looks like the remedies suggested for what you described go to permissions.
What is the folder that you are saving to?
a. Go to that folder and set its Permissions in its Properties.
b. Or create a folder and set Permissions in its Properties and then direct the Save In to that folder
Please let us know if that works for you.