What causes error 3019,1 ?

I have had error 3019,1 four times in about 3 months. I followed the instructions here:

https://support.norton.com/sp/en/us/norton-360/22.5.2.15/solutions/v74065430_EndUserProfile_en_us?q=3019%2C1

I also clicked "What if this didn't work?" and followed the instructions to remove and reinstall Norton 360.

I also tried Web Chat. As far as I could tell, the Norton technician just repeated the steps I had previously undertaken.

I have Windows 7 Home Premium with Service Pack 1.