Yes! that actually did it. Sorry I hadn’t quite followed what you meant by the previous post. It looks like some of the ironbug components also require the workaround Chris suggests at the link you shared, and it is still something NREL has not picked up in OS 3.0.1 (not just 3.0.0).
0.15.0.0 seems to be an oversight in versioning.
Bottom line for future readers using LBT1.1 and having similar issues:
1- You need OpenStudio 3.0.1 installed (if you have installed OpenStudioApplication 1.0.1, you still need to do this in addition to OSA)
2- You need v0.16.0.0 of ironbug installed
3- You need to follow this fix