This is a note on how I fixed a relatively minor issue with Microsoft SQL Server Express LocalDB. The solution was a bit difficult to find. Therefore I'm writing this in the hope that it will be found by other people who have the same problem and Google the error message text. This is based on a StackOverflow answer by Yennefer. I've added a bit more detail and an alternative way to delete the triggers. I'm leaving out most of my mistakes, several dead ends, etc.
I'm certainly no expert on anything in this document. I'm just sharing what worked for me.
When I opened Microsoft's Volume Activation Management Tool (VAMT) and tried to connect to my LocalDB instance as usual, I got this error: