On the off-chance it might work, I ran the Dell Update app to see what it would do. It found an OS Recovery update, among other things. After installing and restarting, and allowing Dell Update to finish some unexplained "operation" that it insisted it had to complete, I ran it again and got "system up to date." I then ran SupportAssist's "Get Drivers and Downloads" and it completed successfully, for the first time ever, with a green "None available" and no error message. This is on a new XPS 8930 running Win10 1909.  
Hi, my Dell Inspiron 17 (Inspiron 57770) with SupportAssist 3.4.0 is not running the drivers scan correctly since dec.10 and is giving me an 'unexpected error'. All other functions works correctly. How can I solve the problem? Thanks in advance Fabrizio
Dell SupportSaaist 3.4 non updating drivers