Years ago, when using Elements 2 on a Dell, I had this same problem. After using Save to Web to then Preview (using the web) thousands of animations and graphics, I got an error message that stated I could not Preview. Now, I am getting the error message "Access to file denied." I am using Elements 15 on an iMac (2017). I have to believe that the solution to my problem is emptying all the temporary files stored in a Cache folder. But I am having no luck finding that folder. I have tried numerous paths to looking for such files in my Adobe folders, but to no avail. I also have tried to follow paths suggested for emptying both browser caches and my iMac hard drive caches.
Macs are usually pretty good about clearing all the "temp files" themselves, but if your one that leaves your mac running 24/7, restarting your mac every so often will generally allow for completion of the pre scheduled maintenance tasks that macs do.
Jeff, I have plenty of storage (192 GB.) I followed your path and ended up in the folder SaveforWeb which was in the folder TemporaryFiles which was in the folder "T," which was in another folder with a long name of gobblygook which was in a folder "3P." There was nothing in the SaveforWeb folder except one file.
Anyway, I really thank you for looking into this for me. I have been trying other options involving the broswers I use, my hard drive, and the Elements 15 program. I have had no luck, but it sure is nice that someone will at least look at a problem and offer sound advice. Thanks again. It is much apprecited.