See my post above!!!
Mike, the SMF extension was last worked on by Dave Capro who released version 7.0 about 5 or 6 years ago. Dave was not the creator or the originator. There were several people involved. I had the same problem as the OP and was hoping for some help from other users more knowledgeable and skillful than myself.
Sometime ago, I forked SMF-Extension and added new functions to retrieve historical stock data from Yahoo (see SMF-Extension-Fork). Unfortunately, Yahoo terminated the historical stock data service somewhere around 5/15/2017 and I had to fall back to a lesser Google service that only reliably provides historical closing prices.
Today, I changed the Yahoo URL from finance.yahoo.com to download.finance.yahoo.com. This should fix the problems discussed in this thread. If you are interested in giving the updated extension a try, you can find it here.
I am unable to install SMF 8.6 on LO 5.2.7. New at this and I could use some help.
john