I've just broken my Tridion system. I had a perfectly good SDL Web 8.1.1 installation, and I've broken it upgrading to 8.5. This is really annoying. I'm gritting my teeth as I type this, and trying not to actively froth at the mouth. It's annoying for two reasons: 

1. The documentation told me to 
2. I got burned exactly the same way going form 8.1 to 8.1.1 and I don't seem to have learned my lesson. 

So what exactly am I ranting about? Let me explain. 

Take the discovery service as an example, but the same thing applies to the other services. Look at the documentation for Upgrading the Discovery Service. Check out the highlighted line below: 

Doing this goes against the grain for anyone with experience of setting up servers. Copying a clean "known good" situation over a possibly dirty implementation and expecting it to work is asking for trouble. I'd never have written these instructions myself. What on earth was I thinking when I blindly followed them? 

The service directory that you're attempting to overwrite contains a lib directory full of jars, and a services directory containing yet two more directories of jars. What you want to do is replace the jars with their new versions. This would be fine if all the jars had the same name as before, and there weren't any that shouldn't be there any more. As it is, the file names include their version numbers, so you end up with both versions of everything, like this: 

This results in messages like "Class path contains multiple SLF4J bindings" and ensures that your services don't start. The solution is simple enough. Go to the various directories, and make sure that they contain only the jars from the 8.5 release. 

Fortunately, I'm still feeling very positive about the folks at SDL in the wake of having received the MVP award again. I suppose I'll forgive them.... once I finish cleaning up the rest of my services. 

Update: After posting this fairly late last night, it's now not even lunch time the following day, and I've already been informed that SDL have seen this, and are already taking action to update the documentation. That's pretty good going. Thanks