I've been advised against upgrading by two of my friends. The wife of one of them found that Win10 was incompatible with Outlook – apparently she could receive emails, but not send them.The other tried to upgrade, and encountered numerous problems typified by the error message above. Among them were incompatibilities with the AVG security package and others that I cannot remember off-hand. He's now gone back to Win8.1.
It may be different if you get a new computer with a clean install of Win10 as the original operating system, but everybody I've spoken to says that the upgrades don't work well, and in some cases don't work at all.