As mentioned previously, it looks like the upgrader can't find the members table. If I were you, I would try to start the upgrade again.
A word of advice, if I may, make first a duplication of your live forum to a test forum and then upgrade the test forum first to see how things will go. Like that you can take all the time to troubleshoot the errors that might pop up without disrupting the main forum.
Once the test forum has bene upgraded propery, you can proceed with upgrading the main forum.
Hope it helps and good luck.