After loading the opt-in 3.0 Preview, I got this error in debug.err:
Message: ERROR: Tech Tree Audit: Tech Tree Fracture detected. This tech has no valid prerequisite, and is unreachable.[BR]Tech Name: MasterNovelHarvestingTech[BR]Tree: Master_Tree
In Crusade, Master_Tech_Defs.xml starting with line 2648:
I'd guess the Tech option should be a named tech?