"Could not write the file, and unknown error occour" on 2012 with macOSBIGSUR

After installing macOS BIGSUR on my macbook Pro my Elements 2018 stop working and crashed. Now I have upgraded to the new 2021 but there are still problems. When editing my pictures and try to save as web I get the  same error  "Could not write the file, and unknown error occoured"