During our team’s recent upgrade from Sitecore 7.5 (rev. 150212) to 8.1 Update-1, there were a number of tool version incompatibilities, but most weren’t surprising. What I did not expect, however, was that the version of Glass.Mapper we were using would break Sitecore Analytics. We were previously using v.18.104.22.168. The manifestation of this was the Sitecore admin dashboard was showing entirely null data on the graphs:
I did log this on the Glass.Mapper github repo (https://github.com/mikeedwards83/Glass.Mapper/issues/202), but the issue was closed with the explanation that since I said I upgraded to Glass.Mapper v4, and that fixed things, Mike Edwards closed the issue. Lucky for us the upgrade path was quick and painless (really!). Version 4 appears to be backwards compatible, although there are some nice, juicy things updating code can get you (http://glass.lu/Mapper/Sc/Tutorials). After I upgraded, we finally saw data showing up (yay!):
Moral of the Story: Our team wholly underestimated the time upgrading would take us over all, due to unforeseen incompatibilities/bugs. If you’re planning to upgrade to the latest and greatest version of Sitecore, I would highly recommend waiting at least three months for other tools you might be using to catch up. Or at least check with your other tool vendors to make sure they support the latest version of Sitecore.