YAY! Thank you, thank you, Pathoschild! It seems to be working now; it isn't shuddering and crashing like it was when it was throwing up those repeated error messages. It has just listed my mods and mentioned available updates, same as it used to do. I wish I was clear on what I had managed to do to it... I did the beta 15 install perfectly, but then turned around and did something to the beta 16 update... makes me nervous because I proceed very carefully after printing out notes and reading them perhaps five times before I will even give it a try. I probably just tried to get it finished too late in the evening. (That, and hubris.) I'll make a point in subsequent updates to do it in the morning after breakfast!