I'm experiencing the same issue. I have the most recent version of Java (6, Update 32) and I've republished my course in Presenter and I still receive an LMS API error message. We have a license on a couple of computers and I'm receiving the error on the other computer as well. Any thoughts?
Grout needs between 48 and 72 hours to dry before it can be properly sealed. Despite the fact that grout often looks dry within a few hours, sealing it too early can damage the grout and keep it from effectively doing its job. Keep Learning.
And you can start using the shower the day after you caulk. When it comes time to seal the grout, just clean it well and let it dry before sealing. The longer you wait before sealing, the more chance of it getting stained, but just using it for a shower (no food prep) is relatively low risk.