Ive been using Adobe Photoshoot Elements since around 10/14/2016 with no issues.... Today I had download the Nik Filter Collection.... I was using Elements, now all of a sudden it has converted back to the option of license the software or use the trial software for 30 days.
In Help Menu, see if you have not been signed out.
You can click on Sign In and enter your Adobe ID. This will make Editor run in serialized mode again.