A while back, Jamie Krug helped me set up my local ColdFusion multiserver development environment in which I could run ColdFusion 8 and ColdFusion 9 instances on the same code base. Jamie was a super fantastic help and everything was running perfectly fine until, seemingly out of nowhere, my ColdFusion 9 instance died. ColdFusion 8 was working properly; but, whenever I tried to run code through my ColdFusion 9 instance, I got the following JRUN error:
This morning, after weeks of not being able to fix the problem, I finally uninstalled everything (JRUN and ColdFusion) and started again from scratch. After installing JRUN and deploying my ColdFusion 9 and ColdFusion 8 EAR files, things appeared to be on the up-and-up. Once again, I had both servers running successfully in parallel.
That is, until I broke it.... again.
This time, however, I know exactly what I did wrong: I ran the ColdFusion 8.0.1 Updater. I was only intending to target the ColdFusion 8 instance; but, apparently, the updater alters the underlying JRUN installation which, at the time, was the ColdFusion 9 multiserver compatible version. As such, it looks like JRUN is no longer able to work with ColdFusion 9 code.
Oh well, at least I know never to do that again. An hour wasted, but much wisdom gained.